LIBRE CONFIDENTIAL

Light Weight Universal Control Interface

(LUCI)

Technical Note

Module : LSx

Revision: 15.0.7

Libre Wireless Technologies Private Limited

librewireless.com

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Table of Contents 
 
Document Information ............................................................................................................ 8 
1. Abstract ................................................................................................................................................... 8 
2. Targeted Audience .............................................................................................................................. 8 
3. Document Revision History ............................................................................................................. 8 
Definitions ................................................................................................................................... 9 
Introduction to LUCI ............................................................................................................... 10 
LUCI Protocol ............................................................................................................................ 11 
1. LUCI Message Box ............................................................................................................................ 11 
1.1. Message Box Packet Format ................................................................................... 11 
1.2. Cyclic Redundancy Check ...................................................................................... 12 
2. Communication Protocol ............................................................................................................... 13 
2.1. Command and Response ......................................................................................... 13 
2.2. Acknowledgement .................................................................................................. 14 
2.3. GET and SET .......................................................................................................... 14 
LUCI Transport Interface ...................................................................................................... 16 
1. UART Interface .................................................................................................................................. 16 
2. TCP Interface ...................................................................................................................................... 17 
2.1. LSx Discovery using Lightweight SSDP (LSSDP) ................................................ 17 
2.2. Connection and Communication............................................................................. 22 
2.3. Endianness .............................................................................................................. 23 
Getting Started ......................................................................................................................... 24 
1. Document Convention .................................................................................................................... 24 
1.1. Tx-Rx Communication ........................................................................................... 24 
1.2. Feature Message Boxes - Table .............................................................................. 25 
LUCI Message Box Commands............................................................................................. 27 
Features and its Associated Message Boxes .................................................................. 32 
1. LUCI Registration.............................................................................................................................. 32 
1.1. HOST MCU Registration ....................................................................................... 32 
1.2. Network Client Registration ................................................................................... 33 

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2. Audio Playback Management ....................................................................................................... 34 
2.1. Authorization and Playback Info Notifications ...................................................... 34 
2.2. Playback Controls ................................................................................................... 39 
2.3. Playback Status ....................................................................................................... 41 
2.4. Playback Trigger ..................................................................................................... 42 
3. AirPlay .................................................................................................................................................. 51 
3.1. Apple Authentication Co-Processor (ACP) ............................................................ 51 
3.2. AirPlay Password .................................................................................................... 54 
3.3. AirPlay Certification ............................................................................................... 56 
4. TCP Tunneling.................................................................................................................................... 57 
4.1. Server Setup ............................................................................................................ 58 
4.2. Communication ....................................................................................................... 58 
5. OEM App Setup Flow ....................................................................................................................... 60 
5.1. Network Configuration ........................................................................................... 60 
5.2. Device Friendly Name ............................................................................................ 60 
5.3. OTA Update ............................................................................................................ 61 
5.4. Google ToS and User Feedback ............................................................................. 61 
6. Firmware Updates ............................................................................................................................ 64 
6.1. OTA (Over The Air) Update................................................................................... 64 
7. BLE Remote......................................................................................................................................... 71 
7.1. BLE Remote - Work Flow ...................................................................................... 71 
LUCI Message Boxes ............................................................................................................... 74 
1. Rx_MB# 3 (Register Network Clients)...................................................................................... 74 
2. MB# 4 (Deregister Network Clients) - Deprecated ............................................................. 76 
3. RxTx_MB# 5 (Firmware Version Information) ..................................................................... 76 
4. Rx_MB# 6 (HOST MCU Firmware Version) ............................................................................ 77 
5. Rx_MB# 8 (Serial Number) ........................................................................................................... 78 
6. Rx_MB# 9 (Is HOST Present) ....................................................................................................... 79 
7. Tx_MB# 10 (Playback Authorisation) ...................................................................................... 80 
8. Rx_MB# 11 (Playback Authorisation Grant) .......................................................................... 82 
9. MB# 12 (AirPlay Control) – Deprecated.................................................................................. 83 
10. MB#13 (AirPlay Status) – Deprecated ................................................................................. 83 

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11. Rx_MB# 14 (ACP Share Command) ....................................................................................... 84 
12. Tx_MB# 15 (ACP Share Response) ........................................................................................ 86 
13. Tx_MB# 17 (SoftACP Status) .................................................................................................... 87 
14. Rx_MB# 40 (Play Control) ........................................................................................................ 88 
15. Rx_MB# 41 (Browse Control) .................................................................................................. 90 
16. Tx_MB# 42 (UI Info) .................................................................................................................... 93 
17. Tx_MB# 43 (Artwork Metadata) ............................................................................................ 97 
18. Tx_MB# 44 (Airable Track Info) ........................................................................................... 101 
19. Tx_MB# 45 (Play View)............................................................................................................ 102 
20. Tx_MB# 49 (Current Playback Position Time) ............................................................... 104 
21. Tx_MB# 50 (Current Source) ................................................................................................. 105 
22. Tx_MB# 51 (Current Play State) ........................................................................................... 107 
23. Tx_MB# 54 (Playback Error Status) ................................................................................... 109 
24. Tx_MB# 56 (ISBROWSESTATUS) ......................................................................................... 111 
25. Tx_MB# 63 (Remote Source MUTE/UNMUTE) .............................................................. 112 
26. Rx_Tx_MB# 64 (Volume Control)......................................................................................... 113 
27. Rx_ MB# 65 (Firmware Request) - Deprecated.............................................................. 119 
28. Tx_MB# 66 (Firmware Install Progress) ........................................................................... 119 
29. Tx_MB# 68 (HOST Image Ready) ......................................................................................... 120 
30. MB# 69 (Request Firmware Upgrade) - Deprecated ................................................... 120 
31. RxTx_MB# 70 (Preset, Auto USB & Standby) .................................................................. 121 
32. Rx_MB# 76 (Acquire & Play) ................................................................................................. 125 
33. RxTx_MB# 80 (Play Audio Cues) .......................................................................................... 126 
34. RxTx_MB# 90 (Device Name) ................................................................................................ 127 
35. RxTx_MB# 91 (Network Info) ............................................................................................... 130 
36. RxTx_MB# 92 (Device Details) ............................................................................................. 132 
37. Rx_MB# 95 (Input Start) ......................................................................................................... 135 
38. Rx_MB# 96 (Input Stop) .......................................................................................................... 136 
39. Rx_MB# 97 (External Playback) ........................................................................................... 137 
40. Rx_MB# 111 (TCP/IP Tunneling Start) ............................................................................. 139 

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41. TxRx_MB# 112 (Tunnel Data) ............................................................................................... 140 
42. Rx_MB# 114 (Reboot Request) ............................................................................................. 142 
43. Tx_MB# 115 (Reboot Command) ........................................................................................ 143 
44. Tx_MB# 149 (Miscellaneous MCU Requests) .................................................................. 144 
45. MB# 211 (Start Firmware Upgrade) - Deprecated ....................................................... 145 
46. Rx_MB# 213 (Music Service Credentials) ......................................................................... 146 
47. Tx_MB# 223 (Firmware Download Progress) ................................................................ 147 
48. Tx_MB# 230 (Audio Output FS)............................................................................................ 148 
49. Rx_MB# 232 (AC Powered) .................................................................................................... 150 
50. RxTx_MB# 235 (Trigger OTA) ............................................................................................... 151 
51. RxTx_MB# 238 (Forced Upgrade) ....................................................................................... 152 
52. Rx_MB# 556 (Audio Output FS ACK) .................................................................................. 154 
53. RxTx_MB# 561 (Apple Home APP Inclusion Check) .................................................... 155 
54. Rx_MB# 562 (AirPlay Password Request) ....................................................................... 157 
55. Tx_MB# 563 (AirPlay Password Response) .................................................................... 158 
56. Rx_MB# 571 (Google Cast ToS and Usage Report - Requests) ................................. 160 
57. Tx_MB# 572 (Google Cast ToS & Usage Report - Response) ..................................... 163 
58. RxTx_MB# 573 (TimeZone Configuration) ...................................................................... 165 
59. Rx_MB# 611 (MCU-LSx Standby) ......................................................................................... 168 
60. Tx_MB# 612 (LSx-MCU Standby) ......................................................................................... 171 
61. RxTx_MB# 621 (HOST Settings) ........................................................................................... 172 
62. Tx_MB# 622 (HOST Settings Status) .................................................................................. 175 
63. RxTx_MB# 651 (Log Report) ................................................................................................. 177 
64. Rx_MB# 653 (MCU Log Data) ................................................................................................ 179 
65. Tx_MB# 654 (MCU Log Response) ...................................................................................... 182 
66. Tx_MB# 655 (MCU Log Request) ......................................................................................... 183 
67. Tx_MB# 661 (BLE Wi-Fi Config-Event Monitor)............................................................ 184 
68. Rx_MB# 663 (BLE Remote Event Request) ..................................................................... 186 
69. Tx_MB# 664 (BLE Remote Event Response) ............................................................. 187 
70. Tx_MB# 691 (Cellular Mode) ................................................................................................. 188 

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71. Tx_MB# 692 (Cellular Modem Status) ............................................................................... 189 
72. Tx_MB# 701 (OTA LSx Actions) ........................................................................................... 190 
73. Rx_MB# 702 (OTA User Actions) ......................................................................................... 191 
74. Tx_MB# 43690 (LSx LUCI Ready) ........................................................................................ 192 
Message Boxes - Format Upgrade Ahead ..................................................................... 194 
1. RxTx_MB# 7 (Google Cast Version Information) ........................................................... 194 
2. Tx_ MB#36 (USB Device Disconnected) ............................................................................ 195 
3. Rx_MB# 37 (Graceful Shutdown) ......................................................................................... 196 
4. Tx_ MB# 38 (USB Device Connected) ................................................................................. 197 
6. Rx_MB# 72 (Trigger Wi-Fi Scan) .......................................................................................... 198 
7. Tx_ MB# 73 (Get Wi-Fi Scan Results) ................................................................................. 199 
8. RxTx_MB# 123 (Interface IP Address Info) ..................................................................... 200 
9. RxTx_ MB# 124 (Network Status) ....................................................................................... 201 
10. RxTx_ MB# 125 (Network Conf) .......................................................................................... 204 
11. Rx_MB# 127 (Network Reset)............................................................................................... 205 
12. Rx_ MB# 128 (Configure Static Network) ........................................................................ 205 
13. Rx_Message Box 134 (Ethernet Status Notifier) ............................................................ 207 
14. Rx_ MB# 142 (WAC Start) ....................................................................................................... 208 
15. Tx_ MB# 143 (Network Configuration Status) ............................................................... 210 
16. RxTx_ MB# 144 (WAC Stop) .................................................................................................. 211 
17. RxTx_MB# 150 (Factory Reset) ............................................................................................ 212 
18. RxTx_MB# 151 (RSSI) .............................................................................................................. 213 
19. Tx_MB# 205 (AVS Login Status) ........................................................................................... 214 
20. MB# 206 (Region) ...................................................................................................................... 215 
21. Rx_MB# 209 (Bluetooth Control) ........................................................................................ 216 
22. Tx_MB# 210 (Bluetooth Response) .................................................................................... 218 
23. RxTx_MB#208 (NV Read/Write) ......................................................................................... 220 
24. Rx_MB# 212 (SDDP Notifier) ................................................................................................. 222 
25. MB# 222 (Cast OTA Update) ................................................................................................. 224 
26. RxTx_MB# 226 (Cast Update Info) ...................................................................................... 225 
27. RxTx_MB# 229 (Get NTP Time) ........................................................................................... 228 

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10.28. RxTx_MB# 231 (Cast Serial Number)................................................................................. 230

10.29. RxTx_MB# 233 (MIC Control) ............................................................................................... 231

10.30. MB# 234 (AVS APP Service) .................................................................................................. 232

10.31. Tx_MB# 240 (AVS Client Status) .......................................................................................... 235

10.32. RxTx_MB# 246 (Alexa UI) ....................................................................................................... 236

10.33. RxTx_MB# 247 (Enable Speech Tone) ............................................................................... 239

10.34. MB# 248 (AVS Custom Speech) ............................................................................................ 240

10.35. Tx_MB# 494 (Cast Setup Started) ........................................................................................ 241

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1. Document Information

1.1. Abstract

Light-weight Universal Control Interface (LUCI) is a protocol defined by Libre to control

any LibreSync (LS) enabled devices. This document explains LUCI and the specifications for

the message boxes used for LUCI communication between the LSx (LS10/11, LS9/X/AD,

LS6/5B) devices and the HOST MCU or APP.

1.2. Targeted Audience

This document is prepared to provide valuable insights to developers working on both

HOST MCU and Companion APP development. Its primary objective is to provide a

comprehensive understanding of the Libre platform's features and offer guidance on

implementing LUCI communication protocol for seamless interaction with the Libre LSx

platform.

1.3. Document Revision History

Revision

Date

Description of change

Author

15.0.7

Sep 06, 2024

Added MBs: 56, 92, 622, 651, 653,

654, 655, 661, 663, 664, 691, 692,

701, 702

Anoop, Santhosh,

Sampath, Ajit,

Anoop

15.0.6

June 10, 2024

Added OTA MBs

Ranjith C.

15.0.5

Apr 17, 2024

Added OEM MBs

Anoop Rajan

15.0

Apr 03, 2024

New LUCI Document

Anoop Rajan

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2. Definitions

LSx: Libre Sync platform, where “x” can be any of the supported platforms i.e., LS11/LS10

/LS9/LS5B/LS6.

HOST MCU: HOST Microcontroller Unit manages user interfaces, which includes buttons,

touchscreens, LEDs and displays, allowing users to interact with the system.

Companion APP/APP: Companion APP is typically installed on a separate device, such as a

smartphone or tablet and are used to interact with or control the system. In this document

Companion APPs are referred to any network clients.

Content Provider APPs: These are streaming APPs provided by third parties like Spotify,

Roon desktop app, Tidal Connect, etc. which provides access to a vast library of digital

content, including music, podcasts and live broadcasts, typically on a subscription basis.

Message Box (MB): Message boxes are used to establish the communication and exchange

the data in packet format between HOST MCU/Companion APP and LSx.

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3. Introduction to LUCI

LUCI (Light-weight Universal Control Interface) is a proprietary communication protocol

developed by Libre for seamless communication with LSx. Its architectural structure is

specifically tailored to enable developers to establish communication protocols with LSx

products using the LUCI framework. In practice, both HOST MCU and Companion Mobile

APPs can harness the capabilities of the LUCI protocol to control, share data and obtain

status updates from LSx.

Optional Display

Connected to MCU

Host MCU LSx

Optional IR Remote

Connected to MCU

LUCI (UART)

LUCI (TCP)

Buttons

LEDs

Figure 3-1: LUCI Block Diagram

The provided LUCI block diagram illustrates the ideal operational environment. LUCI

serves as a communication bridge, ensuring seamless interaction between the HOST

MCU/Companion APP and LSx.

HOST MCU: HOST MCU manages all actions involving buttons, LEDs, the display,

DAC/DSP/AMP, remote control and more. It interacts with LSx via LUCI over UART

interface.

Companion Application/APP: In this document the Companion APP is abbreviated as

“APP”. Companion APP is used to configure LSx to network, to register/login with the

streaming services (Alexa, Google Cast, etc.), to browse and play, to control the LSx

products, display play view and more. Companion APP interacts with LSx via LUCI over

TCP interface.

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4. LUCI Protocol

LUCI defines a protocol for communicating and controlling LSx through the transmission of

"Message Packets”. It outlines a proprietary format for packaging these messages,

encompassing both data and essential header details.

4.1. LUCI Message Box

The “Message Packets” are organized into a specific proprietary packet structure, referred

to as "Message Boxes" by Libre. Each message is assigned with a unique Message Box ID

and each of these message boxes serves distinct purposes with varying data formats and

command-response behaviours.

4.1.1. Message Box Packet Format

The below figure provides the proprietary LUCI command and response packet format:

Figure 4.1.1-1: LUCI Command and Response Packet

Standard

Command

Description

Remote ID

For LUCI over UART: This serves as a magic number. Should use

0xAAAA for UART (HOST MCU) communication.

For LUCI over TCP: Currently this field is not used. In future this

field can be used to assign unique ID per APP to enhance security.

Command Type

LUCI provides two command types: GET or SET for any

command.

00000001: GET (decimal 1)

00000010: SET (decimal 2)

For more details, refer section 4.2.3

Command

16-bit representation of a command.

Remote ID Command

Type Command Command

Status CRC Data

Length Message Data

16 bit 8 bit 8 bit

16 bit 16 bit 16 bit

Remote ID

(Same as used in

Authentication)

Message Box

Type GET / SET Message Box

ID

Command

Response Status

(Valid for

Command

Response Only) Data Length As Indicated by Data Length

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Standard

Command

Description

This field represents the message box ID.

Command Status

Not applicable for command and response packet.

Valid and non-zero only for Acknowledgement.

0: Invalid and can be ignored

1: Success

2: Generic error

3: Device not ready for specific command

4: CRC error

For more details, refer section 4.2.2

CRC

LSx supports CRC-16-CCITT in the LUCI protocol.

CRC follows ‘Big Endian’ format in LUCI UART HOST MCU

interface

Data Length

Length in bytes of the data payload.

Can be zero if no data is associated

Data

Actual data as specified in the Message-Box. Data field is always a

NULL terminated string type and wherever necessary should be

converted to integer wherever applicable.

If the Data value is mentioned as ‘1’ for any Message-Box, the

value to be interpreted in ASCII of it, that is “0x31”.

4.1.2. Cyclic Redundancy Check

LSx supports CRC-16-CCITT within the LUCI protocol. The CRC calculation encompasses

data from the Remote-ID to the end of the message-data, excluding the CRC field itself, as

illustrated in Figure 4.1-1. Upon receiving the CRC value from the HOST-MCU, LSx

calculates its own CRC and permits data passage only if the HOST-MCU's CRC matches the

LSx-calculated CRC for the received packet.

Customers who prefer not to calculate CRC should transmit a CRC value of “0” and set the

NV-item CRCenable to false. For specific details regarding the NV-item CRCenable, please

refer to the LibreSync_Non-Volatile_Items_TechNote, available in the Libre Portal.

The option to enable or disable CRC checks through NV-item is exclusively available for LS6

and LS9 platforms. For LS10 platform, CRC checks are completely disabled. Further, CRC

check is not applicable for companion APPs.

For any source code requirements related to CRC calculation, please contact Libre

FAE.

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4.2. Communication Protocol

The central aspect of LUCI communication involves external entities like APP/MCU

engaging with LSx through the exchange of LUCI packets.

LUCI predominantly employs a command-response model, allowing either the LSx or

MCU/APP entity to initiate communication by transmitting commands to the other entity.

It's important to note that while some commands necessitate a response, others are simply

directives meant to trigger specific actions.

There is no difference in packet structure between command and response. It’s one and the

same, only difference in context is with the sequence of the events that can occur.

4.2.1. Command and Response

Here is a sample message box that includes both Command and Response.

Command Only: Here is a sample message box that includes only Command for your

reference.

HOST MCU LSx

MB#49 CommandSET

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4.2.2. Acknowledgement

Acknowledgement (ACK) serves the purpose of confirming the receipt of a packet in LSx.

This is applicable only for UART interface, TCP itself have re-transmission and hence LUCI

ACK is not required for TCP. When HOST MCU sends a command, LSx LUCI UART lower

layer on successful reception will send an "ACK". However, LSx employs a selective

approach when it comes to sending ACKs. Not all packets are Acknowledgment, especially

those that already have quick responses, are exempted from the ACK mechanism. This

selective behaviour regarding ACKs is explicitly detailed for each Message Box (MB).

HOST MCU, after sending any packet, it can verify the reception status of that packet from

LSx by checking for its ACK. The absence of an ACK can signal that the packet may not have

reached LSx as intended. In such cases, the HOST MCU can initiate a packet retransmission.

Acknowledgement Format:

Remote ID

Command

Type

Message

-Box ID

Command

Status

CRC

Data Length

0xAAAA

SET

<MB ID>

NA

0

Where <MB ID> is the Message Box ID for which LSx has sent the ACK.

<Cmd status>:

Cmd status

Description

0

Invalid and can be ignored

1

SUCCESS

2

Generic Error

3

Device not ready for specific command

4

LUCI_CRCERROR

4.2.3. GET and SET

GET/SET is a field in LUCI packet structure, termed as "Command Type" field. This is

applicable only for the communication path from HOST MCU/APP to LSx, such that

MCU/APP can either use a GET or SET while issuing a command to LSx.

As per LSx LUCI architecture, LUCI framework internally maintains buffers to store

message box. These buffers will contain the last updated value of each message box. "GET"

command will instruct LSx to provide this last updated value from message box buffers. For

LSx, "GET" reduces overhead, as value can be directly fetched from buffers.

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However, "GET" is applicable only for selected scenarios, such as those outlined below:

- MBs that does not require any frequent updates. e.g.: Getting LSx firmware version.

Firmware version is content and "GET" is recommended as buffer will contain desired

results.

- MBs that LSx framework will update and always keep the latest value. For example,

current volume of the system, LSx always maintains the latest value and “GET” is

recommended here.

"GET" is not recommended for the below scenario:

- Values that are not updated frequently to MB, e.g., "current time", the buffer will not

have latest values. "GET" will result in providing old time here.

“SET” on the other hand instructs LSx framework, to call respective application, act on the

action and provide the updated value/response.

In short SET/GET is specific to a message box, it is well distinguished and explained in the

document across each message boxes on where to use GET or SET, this has to be strictly

followed.

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5. LUCI Transport Interface

LSx offers support for two interfaces, UART and TCP, to facilitate LUCI communication with

external or remote entities like HOST MCU or Companion Apps.

UART is used for LSx-HOST MCU communications.

TCP is used for LSx-Companion APP communications.

Figure 5-1: LUCI Transport Interface

5.1. UART Interface

This is the interface to be used by HOST MCU to communicate with LSx.

The specifications are as follows:

Serial

Settings

Baud Rate

LS9/LS10/LS11: 115200

LS6: 57600

Data Bits

8

Parity

None

Start Bit

1

Stop Bit

1

Flow Control

None

Voltage Levels

3.3V TTL

Refer the respective datasheets of LSx modules for UART pin details.

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5.2. TCP Interface

LSx uses Transport Control Protocol (TCP) for communication with network clients.

Network clients refers to any applications, including companion APPs and remote network

clients, that intend to establish communication with the LSx over a network connection.

The following is the sequence of steps outlining how a companion app can discover,

connect, and communicate with LSx:

Discovery: The companion APP initiates the discovery process to identify LSx products

within the network. This process retrieves the IP address and port number of LSx, allowing

the APP to proceed with establishing a connection and subsequent communication.

Connection and Communication: After discovering LSx, the companion app establishes a

TCP connection to LSx using the port number obtained during discovery. Upon successful

connection, LSx and the companion app can engage in communication using the LUCI

protocol.

5.2.1. LSx Discovery using Lightweight SSDP (LSSDP)

LSx has introduced its proprietary Lightweight SSDP to address the limitations of the

standard Simple Service Discovery Protocol (SSDP). Unlike SSDP, which can be resource-

intensive and requires parsing large device description files, Lightweight SSDP eliminates

the necessity of parsing XML files.

LSSDP works on the same principle of SSDP:

• LSx responds to M-search multicast request sent by the companion APP.

• LSx sends out NOTIFY message after bootup which helps already opened companion

APP to discover the device.

LSSDP packet are simpler and involves simple headers.

Here are some example packets:

M-Search

M-Search Response

LSSDP NOTIFY

M-SEARCH *

HTTP/1.1\r\n

HOST:

239.255.255.250:1

800\r\n\r\n

PROTOCOL:

Version 1.0

HTTP/1.1 200 OK\r\n

USN:cc90932be79b\r\n

HOST:239.255.255.250:1800\r\n

Version:LSSDP 1.0\r\n

FN:0\r\n

FWVERSION:eng.C4A.2273.109.1

\r\n

CAST_FWVERSION:1.56.eng.C4A.

NOTIFY * HTTP/1.1\r\n

USN:cc90932be79b\r\n

HOST:239.255.255.250:1800\r\n

Version:LSSDP 1.0\r\n

FN:0\r\n

FWVERSION:eng.C4A.2273.109.1

\r\n

CAST_FWVERSION:1.56.eng.C4A.

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M-Search

M-Search Response

LSSDP NOTIFY

2273\r\n

CAST_TIMEZONE:\r\n

CAST_MODEL:Tivoli_M2D\r\n

PORT:7777\r\n

DeviceName:M2D Garage speaker

White\r\n

State:S\r\n

NETMODE:WLAN\r\n

SPEAKERTYPE:Wireless

Speaker\r\n

TCPPORT:2020\r\n

WIFIBAND:2G\r\n

SOURCE_LIST:LS10::f7ffffff\r\n

MRAMode:DDMS\r\n

2273\r\n

CAST_TIMEZONE:\r\n

CAST_MODEL:Tivoli_M2D\r\n

PORT:7777\r\n

DeviceName:M2D Garage speaker

White\r\n

State:S\r\n

NETMODE:WLAN\r\n

SPEAKERTYPE:Wireless

Speaker\r\n

TCPPORT:2020\r\n

WIFIBAND:2G\r\n

SOURCE_LIST:LS10::f7ffffff\r\n

MRAMode:DDMS\r\n

5.2.1.1. LSSDP New Headers

The new LSSDP headers includes:

USN: This header specifies the MAC address of the LSx.

Version: This header specifies the version of LSSDP that is used.

FN: This header specifies if this M-Search response is the first notification for a request

from Companion APP.

- 1: First Notification

- 0: Not First Notification

FWVERSION: This header specifies the firmware version of LSx.

CAST_FWVERSION: This header specifies the version of Google Cast running on LSx.

CAST_TIMEZONE: This header is for future purpose.

CAST_MODEL: This header specifies the model of LSx speaker.

PORT: This header specifies the port number to which Companions apps should connect

over TCP for LUCI communication.

DeviceName: This header specifies the friendly name of the LSx speaker.

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NETMODE: This header specifies if LSx is connected to network over Wi-Fi or Ethernet

SPEAKERTYPE: This header specifies the type of LSx speaker.

TCPPORT: This header is for future purpose.

WIFIBAND: This header specifies if LSx is connected to Wi-Fi over 2.4/5G. Not applicable

when LSx is connected to network over Ethernet.

SOURCE_LIST: This header specifies music services and sources supported by LSx. Please

contact Libre FAE for more information on this.

The following headers are applicable only to MRA functionality and not applicable

anymore:

State: DeviceState header includes the current state of the device:

- M: The device is the Audio-Master

- F: Device is in free state and not part of any Zone

- S: It is an Audio-Client to the Zone mentioned in ZoneID header

MRAMode: This header specifies the MRA mode of LSx.

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Discovery sequence between a Companion APP and LSx:

Figure 5.2-1 - A: Discovery Sequence using LSSDP

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Figure 5.2-1 - B: Discovery Sequence using LSSDP

Custom Discovery Protocols: If the Companion App developer intends to utilize a

discovery protocol different from LSSDP, they should get in touch with Libre FAE for

further assistance.

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5.2.2. Connection and Communication

After successfully discovering the device, the companion app should establish a TCP

connection with the LSx device using the port number obtained during the discovery

process. Currently, the port number is set at 7777 but may change in the future. After

establishing a successful connection, the companion app should proceed to register with

LSx using MB#3, refer section 9. Upon successful registration, LSx and the companion app

can engage in communication using the LUCI protocol. The below sequence diagram

illustrates the flow of connection and communication:

Companion APP Connection and Communication

Companion

APP

Discovery

Completed

LSx

Create TCP server on

port 7777 and wait

for connection

Connect to LSx on Port-7777

Register using MB#3

Add to list for further

communication

MB #3 ACK

Communication using LUCI protocol

Figure 5.2-2 - Connection and Communication Sequence

To enhance security, Libre has implemented secure LUCI network communication using

TLS 1.2 on designated platforms. During the TLS handshake process, it is essential for

network clients to provide a certificate signed by Libre's Certificate Authority (CA). For

more comprehensive information, reach out to Libre FAE.

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5.2.3. Endianness

Handling Little Endian (LE) and Big Endian (BE) data in networked systems involves

ensuring that data transmitted between different systems with varying endianness is

correctly interpreted and converted as needed. Several network protocols specify a

standard byte order for data transmission, which is often Big Endian (BE). When receiving

data from the network, it's converted to the HOST's native endianness if it's not already in

that format. This standardization simplifies data exchange between systems.

Though above mentioned is the standard, LSx follows it differently.

On Tx, LSx converts to network order (BE) and sends out the packet. This is as per the

standard.

On Rx, LSx expects LE format from network. This is not as per the standard. This

configuration was established in the distant past and our extensive portfolio of products in

the market prevents any modification due to inherent legacy constraints.

In short, the network clients (like App) should send the packet in LE format and can receive

the packet in BE format.

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6. Getting Started

Step 1: The HOST MCU or APP developer should construct the LUCI framework for their

specific MCU or App in accordance with the specified requirements. Beginning with the

implementation of fundamental components such as UART/TCP transmission and

reception, as well as message box packetization and depacketization modules, is

recommended.

Step 2: In section 8. Features and its Associated Message Boxes, you will find information

regarding the supported features of LSx, along with details about their corresponding

message boxes. Developers should carefully review this section to identify which message

boxes need to be implemented based on the product's requirements.

Step 3: Developers should proceed with the implementation of message boxes one by one,

following the designated sequence and priority. The initial step involves referencing

section 8.1. LUCI Registration and implementing the registration message boxes.

Subsequently, developers should align with the feature list as required and continue with

the implementation of the relevant message boxes in a systematic manner.

6.1. Document Convention

This document consists of two conventions in the relevant sections and it is explained in

detail for user reference:

6.1.1. Tx-Rx Communication

In this document, each message box is named in accordance with the data communication

path, taking LSx as the point of reference.

For example,

HOST MCU LSx

MB#51 SET Command

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The inclusion of the "Tx_" prefix for this message box explicitly signifies that its sole

function is to transmit data from LSx to the HOST MCU (with reference to LSx, it denotes

"Tx").

Below are the possible prefixes:

Prefix

Description

Rx_

LSx will receive the data from HOST MCU.

Tx_

LSx will transmit the data to HOST MCU.

RxTx_

LSx will receive the data from HOST MCU and then transmit the data to HOST

MCU.

TxRx_

LSx will transmit the data to HOST MCU and then receive the data from HOST

MCU.

6.1.2. Feature Message Boxes - Table

In this document, each feature section is accompanied by a table that lists its corresponding

LUCI message boxes, providing users with a helpful reference. For instance, the screenshot

below displays a table extracted from one of the feature sections:

Figure 6.1.2-1: Feature MB Sample

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The highlights of the above table are detailed below:

Sl. No.

Items

Description

1

MB#Number -

Message Box Name

This section contains information regarding message box number

and its associated name. To access comprehensive information about

this message box, simply click here.

2

Description

This section explains the purpose and intended use of the message

box.

3

HOST MCU

This section explains the role of HOST MCU with respect to the

message box.

4

Mandatory/

Optional

This indicates whether it is mandatory or optional for HOST

MCU/Companion APP to implement the specific message box.

5

Companion

APP/APP

This section explains the role of Companion APP with respect to the

message box.

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7. LUCI Message Box Commands

MB Number

Decimal

(Hex)

Direction

Message Box Name

Response

LUCI Registration

3 (0x3)

LSx → APP

Register Network Clients

No

9 (0x9)

HOST MCU → LSx

Is HOST Present

No

43690

(0xAAAA)

LSx → HOST MCU

LSx LUCI Ready

Yes, MB#9

Media Player and Playback Sequence

10 (0xA)

LSx → HOST MCU

Playback Authorisation

Yes, MB#11

11 (0xB)

HOST MCU → LSx

Playback Authorisation Grant

No

40 (0x28)

HOST MCU/APP → LSx

Play Control

No

41 (0x29)

HOST MCU/APP → LSx

Browse Control

Yes, MB#42

42 (0x2A)

LSx → HOST MCU/APP

UI Info

No

43 (0x2B)

LSx → HOST MCU

Artwork Metadata

No

44 (0x 2C)

LSx → HOST MCU/APP

Airable Track Info

No

45 (0x2D)

LSx → HOST MCU/APP

Play View

No

49 (0x31)

LSx → HOST MCU/APP

Current Playback Position

Time

No

50 (0x32)

LSx → HOST MCU/APP

Current Source

No

51 (0x33)

LSx →HOST MCU/APP

Current Play State

No

54 (0x36)

LSx →HOST MCU/APP

Playback Error Status

No

63 (0x3F)

LSx → HOST MCU/APP

Remote Source

MUTE/UNMUTE

No

64 (0x40)

LSx ↔ HOST MCU/APP

Volume Control

Yes

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MB Number

Decimal

(Hex)

Direction

Message Box Name

Response

70 (0x46)

HOST MCU/APP ↔ LSx

Preset, Auto USB & Standby

Yes

76 (0x4C)

HOST MCU → LSx

Acquire & Play

No

80 (0x50)

HOST MCU ↔ LSx

Play Audio Index

Yes

95 (0x5F)

HOST MCU/APP → LSx

Input Start

No

96 (0x60)

HOST MCU/APP → LSx

Input Stop

No

97 (0x61)

HOST MCU/APP → LSx

External Playback

No

213 (0xD5)

HOST MCU/APP → LSx

Music Service Credentials

No

230 (0xE6)

LSx → HOST MCU

Audio Output FS

Yes, MB#556

556 (0x22C)

LSx → HOST MCU

Audio Output FS ACK

No

AirPlay

14 (0xE)

HOST MCU → LSx

ACP Share Command

Yes, MB#15

15 (0xF)

LSx → HOST MCU

ACP Share Response

No

17 (0x11)

LSx → HOST MCU

SoftACP Status

No

561 (0x231)

HOST MCU → LSx

Apple Home APP Inclusion

Check

Yes

562 (0x232)

HOST MCU → LSx

AirPlay Password Request

Yes, MB# 563

563 (0x233)

LSx → HOST MCU

AirPlay Password Response

No

TCP Tunneling

111 (0x6F)

HOST MCU → LSx

TCP/IP Tunneling Start

No

112 (0x70)

HOST MCU → LSx

Tunnel Data

No

Setup

91 (0x5B)

HOST MCU → LSx

Network Info

Yes

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MB Number

Decimal

(Hex)

Direction

Message Box Name

Response

Standby

611 (0x263)

HOST MCU → LSx

MCU-LSx Standby

Yes, MB# 612

612 (0x264)

LSx → HOST MCU

LSx-MCU Standby

Yes, MB# 611

HOST-MCU

621 (0x26D)

HOST MCU → LSx

HOST Settings

Yes

OTA

6 (0x6)

HOST MCU → LSx

HOST Firmware Version

Yes

66 (0x42)

LSx → HOST MCU

Firmware Install Progress

No

68 (0x44)

LSx → HOST MCU

HOST Image Ready

No

114 (0x72)

LSx → HOST MCU

Reboot Request

Yes, MB#115

115 (0x73)

HOST MCU → LSx

Reboot Command

No

223 (0xDF)

LSx → HOST MCU

Firmware Download Progress

No

232 (0x E8)

HOST MCU → LSx

AC Powered

No

235 (0x EB)

HOST MCU ↔ LSx

Trigger OTA

Yes

238 (0x EE)

HOST MCU ↔ LSx

Forced Upgrade

Yes

BLE Remote

663 (0x297)

HOST MCU → LSx

BLE Remote Event Request

Yes

664 (0x298)

LSx → HOST MCU

BLE Remote Event Response

No

General

5 (0x5)

HOST MCU ↔ LSx

Firmware Version Info

Yes

6 (0x6)

LSx ↔ HOST MCU

HOST Version Information

Yes

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MB Number

Decimal

(Hex)

Direction

Message Box Name

Response

8 (0x8)

HOST MCU → LSx

Serial Number

No

149 (0x95)

LSx → HOST MCU

Miscellaneous MCU Requests

Yes, MB# 150

MB Number

Decimal

(Hex)

Direction

Message Box Name

Response

Message Boxes – Format Upgrade Ahead

7 (0x7)

HOST MCU ↔ LSx

Google Cast Version Info

Yes

36 (0x24)

LSx → HOST MCU

Device Disconnected

No

37 (0x25)

HOST MCU → LSx

Graceful Shutdown

No

38 (0x26)

LSx → HOST MCU

Device Connected

No

72 (0xE)

HOST MCU → LSx

Trigger Wi-Fi Scan

Yes, MB#73

73 (0xF)

LSx → HOST MCU

Get Wi-Fi Scan Results

No

90 (0x5A)

HOST MCU → LSx

Device Name

Yes

123 (0x7B)

HOST MCU ↔ LSx

Network Info

Yes

124 (0x7C)

LSx → HOST MCU

Network Status

No

125 (0x7D)

HOST MCU → LSx

Network Conf

Yes, MB#124

127 (0x7F)

HOST MCU/APP → LSx

Network Reset

No

128 (0x80)

HOST MCU → LSx

Configure Static Network

No

134 (0x86)

HOST MCU → LSx

Link Status

No

142 (0x8E)

HOST MCU → LSx

WAC Start

Yes, MB#143

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MB Number

Decimal

(Hex)

Direction

Message Box Name

Response

143 (0x8F)

LSx → HOST MCU

Network Configuration Status

No

144 (0x90)

HOST MCU ↔ LSx

WAC Stop

Yes

150 (0x96)

HOST MCU ↔ LSx

Factory Default

Yes

151 (0x97)

HOST MCU ↔ LSx

RSSI

Yes

205 (0xCD)

HOST MCU ↔ LSx

AVS Login Stat

Yes

206 (0xCE)

HOST MCU → LSx

Region

No

208 (0xD0)

LSx ↔ HOST MCU

NV Read/Write

Yes

212 (0xD4)

HOST MCU → LSx

SDDP Notifier

No

222 (0xDE)

LSx → HOST MCU

Cast OTA Update

No

226 (0xE2)

HOST MCU ↔ LSx

Cast Update Info

Yes

229 (0xE5)

HOST MCU → LSx

GET NTP Time

Yes

231 (0xE7)

HOST MCU ↔ LSx

Cast Serial Number

Yes

233 (0xE9)

HOST MCU → LSx

LSx → HOST MCU

MIC Control

No

234 (0xEA)

HOST MCU → LSx

LSx → HOST MCU

AVS APP Service

No

240 (0xF0)

LSx → HOST MCU

AVS Client Status

No

246 (0xF6)

HOST MCU ↔ LSx

Alexa UI

Yes

247 (0xF7)

HOST MCU ↔ LSx

Enable Speech Tone

Yes

248 (0xF8)

HOST MCU → LSx

AVS Custom Speech

No

494 (0x1C1)

LSx → HOST MCU

Cast Setup Started

Yes

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8. Features and its Associated Message Boxes

8.1. LUCI Registration

To initiate LUCI communication, the initial step involves HOST MCU and Network clients

registering with LSx.

8.1.1. HOST MCU Registration

Once the LSx platform completes its boot-up and initializes all essential modules, LSx

notifies the HOST MCU through MB#43690 that it is ready for LUCI communication. In

acknowledgment, the HOST MCU should respond through MB#9.

MB#9 Confirms that HOST is present

HOST MCU LSx

MB#43690 LSx LUCI Readiness

Regular Message Exchange Continues

HOST MCU registration message boxes in LUCI are:

MB#43690 – LSx LUCI Ready

Description

LSx notifies HOST MCU on its readiness for LUCI communication.

HOST MCU

Mandatory

It is crucial that HOST MCU should initiate LUCI communication only

after receiving this MB. LSx will send this MB by end of its bootup

process and it is fairly assumed that HOST MCU should have booted

up earlier and will be waiting for this MB.

APP

Not Applicable.

MB#9 – Is HOST Present

Description

HOST MCU acknowledges MB#43690 and responds using this MB.

HOST MCU

Mandatory

HOST MCU should compulsorily implement this MB and notify LSx.

APP

Not Applicable.

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8.1.2. Network Client Registration

LSx employs the proprietary LUCI protocol to communicate with external devices, offering

interface options through UART (HOST MCU) or network (network clients).

Network clients refers to any Applications, including companion APPs and remote network

clients that intend to establish communication with LSx over a network connection. Libre

utilizes the TCP protocol for its interactions with these network clients.

After establishing a successful TCP connection with LSx, network clients should register to

LSx using MB#3. MB#4 is used for Deregistration, however, it is deprecated and not used in

the platform.

APP LSx

MB#3 Register Network Clients

Registration message boxes in LUCI are:

MB#3 – Register Network Clients

Description

Register network clients to LSx.

HOST MCU

Not Applicable.

APP

Mandatory

All network clients should use MB#3 and register themselves to LSx.

MB#4 - Deregister Network Clients (Deprecated)

Description

Deregister network clients (This MB is no longer used as it is

deprecated).

HOST MCU

Not Applicable.

APP

Not Applicable.

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8.2. Audio Playback Management

This section details on the message boxes involved in audio playback trigger, notification,

control and status.

A user can initiate playback using the methods like Content Provider APP (Spotify, Tidal,

etc.), Companion APP (Browse & Play), Bluetooth, AirPlay, Button trigger (to play from pre-

sets) and more.

Whenever a new playback request is initiated through any of these actions, it involves LUCI

communication between the LSx device and HOST MCU/APP and the below sections

outlines these with respect to audio player. Broadly, LUCI communication involved here

can be categorized into four sections: Authorization and Playback Info Notifications,

Playback Controls, Playback Status and Playback Trigger.

8.2.1. Authorization and Playback Info Notifications

This section details on how we communicate with HOST MCU about the new playback and

obtain permission from HOST MCU to carry forward (Authorization). It also covers various

notifications related to playback information, such as the current source, volume, metadata,

album art and more, which are sent to the HOST MCU/APPs.

8.2.1.1. Authorization

When a new playback is initiated, LSx will request authorisation from the HOST MCU and

the HOST MCU assesses whether the new playback source should be permitted or not and

provide the response back to LSx.

LSx notifies HOST MCU via MB#10 whenever there is a new playback request or a change

in playback source and HOST MCU verifies if the new source can take control over the

current one and communicates its decision in MB#11.

HOST MCU LSx

MB#11 Allow/Disallow

MB#10 Playback Change Request

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Authorisation message boxes in LUCI are:

MB#10 – Playback Authorisation

Description

LSx requests HOST MCU to grant permission to proceed with the

playback from the new source and then waits for response.

HOST MCU

Mandatory

HOST MCU may perform any necessary actions, such as

• Change the audio route in DSP for LSx playbacks, prepare the

DSP with any specific settings like gain table particular for LSx

playback.

• Waking the device from standby/sleep mode.

The above actions are optional and specific to HOST MCU

implementation.

The HOST MCU can subsequently grant permission in MB#11 after

completing the aforementioned tasks or any other task as deemed

necessary.

APP

Not Applicable.

MB#11 - Playback Authorisation Grant

Description

HOST MCU to grant or deny permission for new playback request.

HOST MCU

Mandatory

HOST MCU can grant or deny permission, once the essential tasks

outlined earlier are completed. Without this permission, LSx will not

proceed with the playback.

Though flexibility is provided to deny the LSx playback request

based on any precedence, this may impact user experience and

music certifications. Hence, MCU engineers need to discuss with

Libre FAE if they wish to deny the permission for any use case.

APP

Not Applicable.

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8.2.1.2. Playback Info Notifications

LSx provides various Playback info such as current source, current playback time,

metadata, artwork and cover art, volume control, etc. to HOST MCU/APP, these data can be

employed for updating the UI display or for maintaining and managing the device's internal

state.

HOST MCU LSx

MB#50

MB#51

MB#54

MB#43

MB#42

MB#49

MB#64

Current State

Play Status (Playing,)

Error Status

Album Art

Meta Data

Playback Position

Volume

MB#230 Audio Output FS

MB#556 Audio Output FS ACK

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Playback Info Notification message boxes in LUCI are:

MB#50 - CURRENT_SOURCE

Description

Used by LSx to inform the HOST MCU/APP on the presently chosen

audio source for playback.

HOST MCU

Optional

• HOST MCU/APP can display the current source information on

its UI/LED. E.g., it can display the source logo or any related

information.

• It can also be used for any internal implementation to

manage/book keep.

APP

MB#230 – AUDIO_OUTPUT_FS

Description

Used by LSx to notify the sampling frequency change to HOST MCU.

Applicable only for systems that supports Dynamic Frequency

Sampling rates.

HOST MCU

Optional

HOST MCU can adjust the DSP/DAC settings (if any) on this sampling

rate change notification. After sending the new sampling rate, LSx

waits for maximum of 1 sec for the response on MB#556. On receiving

the response (or on timeout) LSx assumes that HOST MCU has done the

required changes and LSx starts the playback.

APP

Not Applicable.

MB#556 - AUDIO_OUTPUT_FS_ACK

Description

Send from HOST MCU to LSx acknowledging MB#230

HOST MCU

Optional

On receiving MB#230, HOST MCU can undertake essential

adjustments, such as configuring the DAC/DSP to accommodate the

updated sampling frequency and then acknowledge over MB#556 so

that LSx can proceed with the playback.

APP

Not Applicable

MB#51 – Current Play State

Description

Used by LSx to inform the HOST MCU about the current play state

(playing, paused, stopped) of LSx.

HOST MCU

Optional

• To update the UI/LED

• To maintain the internal state, which can be used to perform

APP

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appropriate actions. E.g., When HOST MCU maintains a single

button for Play/Pause, HOST to refer the internal state to trigger

Play or Pause using MB#40.

MB#54 – Playback Error Status

Description

Used to determine whether the playback control events

(Pause/Resume, Next/Previous, Repeat/Shuffle) are success or failure.

HOST MCU

Optional

Update the UI with proper error notification in case of playback failure

of the given source like Airable (server not reachable, server not found,

timeout, decoders unavailable, sample rate not supported, etc.),

network failure, unexpected errors, etc.

APP

MB#43 - ARTWORK_METADATA

Description

Used to send the album art information to the HOST MCU enabling it to

refresh its display.

HOST MCU

Optional

Applicable only if HOST MCU have a display.

To update the UI display.

APP

Not Applicable (APP to fetch album art from the album art URL

directly)

MB#42 – UI Info

Description

Provides the UI info like play view inf and Browse view info.

HOST MCU

Optional

• Applicable only if HOST MCU have display.

• Update the play view screen using Play view info.

• Update the browsing UI using browse view.

APP

Optional

• Update the play view screen using Play view info.

• Update the browsing UI using browse view.

MB#49 – CURRENT PLAYBACK POSITION_TIME

Description

Notifies the current playback position time of the music being played.

HOST MCU

Optional

• Periodically updates the progress bar.

APP

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• Updates display with playback position time.

MB#64 – VOLUME CONTROL

Description

Used for sending current volume to HOST MCU/APP on playback

initialisation. On initializing a playback from content provider APP, LSx

is supposed to notify some of these APPs with the current volume to

sync the content provider APP volume to device volume. After this as a

confirmation, content provider APPs provide the current volume to LSx

and LSx notifies this volume to HOST MCU/APP as a generic design.

HOST MCU

Optional

Unless user changes the volume explicitly, there will not be any volume

changes on playback initialisations. Hence HOST MCU/APP will not

have any specific action to take here as there is no explicit vol change

in this scenario. LSx will follow this as a general practice however,

HOST MCU/APP can check the current volume with the new volume

and ignore if there is no volume change.

APP

8.2.2. Playback Controls

User can control the playback (Pause, Stop, Next, Previous, Repeat, Shuffle, etc.) either by

using the HOST MCU button or through content provider APP or companion APP. These

playback controls from HOST MCU/APP can be notified to LSx by several message boxes as

explained below.

MB#40

MB#63

MB#64

Playback Control

Mute/Unmute Control

Volume Control

LSxHOST MCU

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Playback Control message boxes are:

MB#40 – Play Control

Description

Used to notify LSx with Play Control commands such as Play, Pause,

Stop, Next, etc.

HOST MCU

Optional

• Issue respective play controls on button presses.

• Issue respective play controls when actions are performed on

the device display.

APP

MB#63 - Remote SOURCE MUTE/UNMUTE

Description

Used to perform audio mute/unmute

HOST MCU

Mandatory

• Mute/unmute the CODEC/DSP.

• Update UI/LED

• Maintains internal records

APP

Optional

• Update UI/LED

• Maintains internal records

MB#64 – Volume Control

Description

Used for Volume control.

HOST MCU

Mandatory

There are various scenarios in which the user can change the volume.

In all these cases, LSx will eventually update HOST MCU with the final

volume. Upon receiving it, HOST MCU should:

• Update the volume setting in the external DAC/DSP/AMP.

• Update UI/LED.

• Keep track of the updated volume for internal reference. E.g., If

user presses vol+ button, HOST MCU should increment on top of

the existing volume.

APP

Mandatory

On volume change notification from LSx:

• APP should update the UI.

• Keep track of the updated volume for internal reference. E.g., If

user changes the volume, APP should increment on top of the

existing volume.

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8.2.3. Playback Status

All the MBs mentioned here are notified to HOST MCU/APP in the process of staring a

playback as mentioned in section 2. Playback Info Notifications. However, there are

instances where this information has to be read again. For example, if the user closes the

Companion APP during playback and then reopens it, the playback screen should be

reloaded with the relevant data, the same can be applicable for HOST MCU to update the

display. This can be accomplished by reading the status notification message boxes.

MB#50

MB#51

MB#42

MB#64

Current State

Play Status (Playing)

Meta data

Volume

LS10HOST MCU

MB#50 GET

MB#51 GET

MB#42 GET

MB#64 GET

Playback Status message boxes in LUCI are:

MB#50 - CURRENT_SOURCE

Description

HOST MCU/APP to read and get the current source that is selected.

HOST MCU

Optional

• HOST MCU/APP can display the current source information on

its UI/LED. E.g., it can display the source logo or any related

information.

• It can also be used for any internal implementation to

manage/book keep.

APP

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MB#51 – Play State

Description

HOST MCU/APP to read and get the current play state of LSx.

HOST MCU

Optional

• To update the UI/LED

• To maintain the internal state, which can be used to perform

Appropriate actions. E.g., When HOST MCU maintains a single

button for Play/Pause, HOST to refer the internal state to

trigger Play or Pause using MB#40.

APP

MB#42 -_UI Info

Description

Used by LSx to send meta data to the HOST MCU/APP to update

display.

HOST MCU

Optional

To update the UI display

MB#64 – Volume Control

Description

HOST MCU/APP to read and get the current volume status.

HOST MCU

Optional

To read this MB and update the status. In most of the cases, HOST

MCU/APP will be maintaining an internal copy of current volume and

hence, this status might not be required. However, this option will be

available to read the current volume to meet any requirements.

8.2.4. Playback Trigger

Users have multiple methods to initiate music playback on the LSx, and this section outlines

the message boxes utilized to trigger these playback actions. The various methods for

commencing playback are as follows:

8.2.4.1. By using Content provider APPs, AirPlay, Bluetooth, Voice

This includes playing music from content provider APPs such as Spotify, ROON, AirPlay,

TIDAL, bubble UPnP, etc. wherein these APPs will provide the selected song/playlist to LSx

using the respective protocols they follow and LSx will initiate these playbacks. AirPlay and

Bluetooth playbacks will also be handled directly by LSx framework. Playing the music

using AVS (Voice) is handled by AVS SDK and notified to LSx player internally.

All of these scenarios are managed internally by the LSx and does not involve any message

boxes for playback trigger.

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8.2.4.2. Browse & Play (LSx managed browsing sources)

This section includes browsing and playing for the sources for which LSx manages the

browsing content. For instance, in USB playback, LSx directly interacts with the USB pen

drive, LSx navigates through the USB file/folder structure according to the browse controls

provided by a user interface such as a content APP or the HOST MCU display.

Through the companion APP or the HOST MCU display, users have the capability to

navigate USB, DMR, Airable, etc. to select and play songs according to their preferences.

The HOST MCU/APP issues browse commands via MB#41, prompting LSx to explore the

designated sources and send the browse view via MB#42. Users can continue browsing

until they locate a song or playlist they wish to play. LSx continuously monitors MB#41

control commands, and when it receives a playable content, it proceeds with the playback

accordingly.

If the companion APP/HOST MCU display browses the content directly from the content

provider (not depending on LSx browsing) this section and message boxes are not

applicable.

MB#41

MB#42

MB#45

Browse Control

UI Info

GET UI Play

LS10HOST MCU

MB#41 - Browse Control

Description

Used by any interface controller (e.g., HOST-MCU over UART / I2C or

Phone APP over Network) to control the selection of Enter, Back, Up,

Down and Select Item Commands

HOST MCU

Optional

Control commands respective UI. Button or test display user

navigation.

APP

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MB#42 - UI Info

Description

Used by LSx to send the Play View/ Browse View contents to the

HOST MCU/APP for display.

HOST MCU

Optional

• Applicable only if HOST MCU has display.

• To update the browse view/play view.

APP

Optional

• Applicable if the companion APP supports the Now Playing

screen or supports LSx browsable contents.

• To update the browse view/play view.

MB#45 – Play View

Description

When the Play View is overwritten by Browse View, HOST MCU/APP

can get the play view information using this MB.

HOST MCU

Optional

• Applicable if the HOST MCU supports display.

• If the user moves from the play view screen to another screen

and then returns to play view, this MB can be used to retrieve

play view details.

APP

Optional

• If the user moves from the play view screen to another screen

and then returns to play view, this MB can be used to retrieve

play view details.

• Also, applicable if APP supports cascaded screen for play view

and browse view.

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Music Service Login Credentials

When the product supports browsable music services like Airable Sources that demands

user login before, the user entered credentials are to be passed to LSx for logging into the

particular music service. MB# 213 is employed to support this.

MB#213 – Music Service Credentials

Description

Used to provide login credentials of music service to LSx when the

service is browsed and played using LSx browsing.

HOST MCU

Optional

• Applicable if the HOST MCU supports display and supports LSx

browsable music services like Airable.

• Provide the user entered login credentials to LSx.

APP

Optional

• Applicable if the APP supports LSx browsable music services

like Airable.

• Provide the user entered login credentials to LSx.

Airable Track Info

To meet the Airable certification requirements and for better UX, LSx provides the detailed

info for track/album such that UI can display this information whenever user opts for it.

HOST MCU/APP can request info about Album/Artist/Track for Airable sources through

MB#41 and the respective details will be sent over MB#44 by LSx.

HOST MCU/APP LSx

MB#41 SET Command (SELECTINFO:<index>)

MB#41 Ack

MB#44 SET Response

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MB#44 – Airable Track Info

Description

Provides info about Album/Artist/Track for Airable sources

HOST MCU

Optional

Applicable only for the products which have display. It is mandatory

to display the track info to meet Airable certification requirements.

APP

Mandatory

It is mandatory to display the track info to meet Airable certification

requirements. IF the APP implements Airable browsing directly using

Airable SDK, this MB is not applicable as it can fetch this info from the

Airable cloud.

8.2.4.3. Audio Input Sources

Input sources refer to the connections or interfaces used to link audio sources to a system.

These sources include inputs such as AUX-in, SPDIF-in, USB-in and more.

The LSx system offers two primary design options for interfacing with these sources.

a. External Sources

In this scenario, the input sources are not directly connected to the LSx module but are

instead linked to an external DSP/DAC. These external DSP/DAC units have the capability

to connect to various sources such as AUX, USB, SPDIF, HDMI and more. They perform the

necessary processing and directly play out the audio. For LSx, all of these sources are

categorized as "external sources" and LSx doesn't need to differentiate between them.

Typically, there are buttons associated with these inputs and when a user presses one, the

HOST MCU can initiate playback using MB#97. In response, LSx switches the source type to

"external" and stops the current playing source (if any).

MB#97 – External Playback

Description

Used to notify LSx on “Start” or “Stop” of external playback (playback

from any sources like AUX, SPDIF, etc.)

HOST MCU

Optional

If there is no requirement to input audio sources directly into the LSx,

and if the external DSP/DAC can support this, OEM/ODM can design

these sources as external.

This Approach is more relevant for input sources that LSx does not

support like HDMI-ARC.

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The HOST MCU can assign these buttons (SPDIF-IN, AUX-IN, HDMI-IN,

etc.) to trigger playback using MB#97.

APP

Not Applicable

b. Internal Input Sources

In this design, the input sources will be directly read by LSx. For instance, SPDIF (directly

connected to LSx) or an Aux In (Analog input connected to an external DAC, DAC providing

it via I2S, LSx reads through I2S-IN). To trigger these input sources, buttons are made

available to end users. Upon user input, the HOST MCU can then initiate the corresponding

input playback using MB#95.

MB#95 – Input Start & MB#96 – Input Stop

Description

Used by the HOST MCU to switch the audio source to line input

sources like AUX, SPDIF, etc. and MB#96 used by the HOST MCU to

stop the audio input sources described in MB#95

HOST MCU

Optional

It is not advisable to route these input sources to LSx and load LSx

unnecessarily unless there is a valid reason to do so. SPDIF-IN in LS10

becomes a valid use case if the customer's DAC does not support

SPDIF-IN. If DSP processing is handled within LSx, it becomes logical

to bring all of these sources into LSx for unified processing.

• When a user presses the corresponding button, the HOST MCU

can initiate the process by calling MB#95 with the appropriate

parameters.

• Additionally, when a user switches to a different source by

pressing the button, HOST MCU should call the stop function

using MB#96.

APP

Not Applicable

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8.2.4.4. Audio Cue

By this mechanism, ODMs/OEMs can include any notification tones in the device firmware

and these tones can be played using MB#80. Each event notification of a device can have its

own distinct tone, allowing for unique sounds like those for successful Wi-Fi connectivity

or Bluetooth pairing.

MB#80 – Play Audio Cues

Description

This message box is used to play custom audio cues for event

notifications.

HOST MCU

Optional

Explore this option if there is a need to enhance the user experience

by playing audio cues for notifications. It can be extended to 3rd party

applications as well.

APP

8.2.4.5. Preset

Users have the capability to save and store their preferred songs in a designated favourite

list. These saved songs can be easily played later using a preset button. MB#70 is used to

trigger this preset button.

Preset Management (MB#70 – Preset Control & Auto USB)

Description

Used to control favorite/presets feature.

HOST MCU

Optional

• To decide on the no. of preset buttons required for the product.

• Design the button spec (e.g., long press on preset button 1 will

save the preset, short press will play)

• Send the respective commands (save, play, delete, etc.) on the

desired button triggers.

APP

Optional

• APP can have UI to display preset buttons and allow actions on

it.

• Send the respective commands (save, play, delete, etc.) on the

desired user clicks.

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8.2.4.6. Direct URL

The HOST MCU/APP can provide LSx with a song or playlist URL through MB#41. LSx will

then retrieve the content from this URL and initiate playback. For playlists, LSx can support

playback controls like next, previous, etc. but for single song URLs, LSx is limited to playing

that individual song.

There are several potential use cases for using direct URLs:

1. From APP to provide Song/Playlist for LSx to play:

It can be any of the below scenarios:

• If the APP implements native browsing by directly interacting with music servers

(e.g., Airable browsing directly with Airable servers), it can provide the final song or

playlist URL.

• If the APP implements DMC (Digital Media Controller), users can browse the content,

and the APP can pass the final playback/playlist URL via direct URL.

• This can be extended to other custom implementations, essentially allowing the APP

to provide a URL to LSx, which LSx can then play.

2. HOST MCU to Provide a URL or Playlist to LSx to Play:

The HOST MCU can provide a playable URL or playlist to LSx for playback.

It's up to the HOST MCU how it fetches the URL, and it can involve various custom

implementations. One common example is the MCU using TCP Tunneling to browse and

eventually present the URL to LSx.

3. Playback of Locally Stored Files:

The HOST MCU/APP can use the direct URL method to play any locally stored tones/files

within LSx by providing the local URL.

Direct URL functionality is supported by MB#41. For more details, refer to MB#41.

Direct URL (MB#41 - Browse Control)

Description

Used by HOST MCU/APP to play the song from a URL.

HOST MCU

Optional

It can be implemented if there is a requirement for any of the use

cases mentioned above.

APP

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8.2.4.7. Quick-Start Source

Suppose a user is currently playing AirPlay but then decides to resume Spotify from where

they left off, how can they restart Spotify with just a single tap? This feature provides a

solution by seamlessly picking up and playing such sources from either their previous state

or the beginning.

Some of the music sources like Spotify can be resumed from its previous state by a simple

button press. This is beneficial as it avoids the hurdle of user browsing and playing using

the APPs. USB/hard disc playback also supports this feature where in with a button press,

LSx can initiate USB/ hard disc from the first song in the drive.

MB#76 provides the option to initiate USB playback. This MB can be extended to support

the similar requirements from more sources.

MB#70 is used currently to provide support for USB playback. We plan to migrate this

option to MB#76 in near future.

USB Playback (MB#70 – Preset, Auto USB & Standby)

Description

Used for USB automatic playback

HOST MCU

Optional

Applicable only if there is a dedicated button in HOST MCU to initiate

USB/Hard Disc playback.

On pressing USB button LSx will initiate USB/Hard Disc playback

from the first song.

APP

Optional

APP can browse and play USB contents, hence this option is mostly

not applicable. However, this can be utilized for any specific

requirements like starting USB playback on a specific icon option

provided.

MB#76 – Acquire & Play

Description

Used for resuming Spotify playback with a single touch.

HOST MCU

Mandatory

This feature is mandated by the Spotify for certification, if the device

supports Spotify as per Spotify guidelines.

As per this, on pressing play button, Spotify should resume from

wherever it was stopped. As most of the product supports multiple

sources, it doesn’t make sense to play Spotify on pressing play button.

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If the HOST MCU supports display, this can be implemented on user

selecting Spotify source from display UI. HOST MCU to send MB#76 in

this case.

APP

Optional

APP can implement this on selecting Spotify source.

8.3. AirPlay

AirPlay is an updated version of Apple's wireless streaming and communication protocol

AirPlay. It enables the wireless transmission of audio, between Apple devices and

compatible third-party hardware.

The LSx platform seamlessly incorporates the AirPlay SDK for AirPlay compatibility. Once

the device is connected to a network, LSx utilizes Bonjour discovery to broadcast its

presence, allowing content provider APPs to detect and display the available speakers.

When a user chooses an AirPlay speaker from any music service, the chosen music is

streamed from their mobile device or laptop to the selected speaker through the advanced

AirPlay technology.

For more details, refer: https://support.apple.com/en-in/HT202809

8.3.1. Apple Authentication Co-Processor (ACP)

ACP is an accessory hardware component that provides device related digital signature

creation and verification services. Apple mandates the inclusion of an ACP in accessories to

enable them for AirPlay streaming. The AirPlay SDK authenticates the accessory, like the

LSx-enabled speaker, by leveraging the capabilities of the ACP. Once a valid challenge-

response is obtained from the ACP, the LSx speaker can proceed with AirPlay streaming.

The ACP is additionally required to provide support for Wireless Accessory Configuration

(WAC), a technology offered by Apple to streamline the network setup of wireless

accessories. It's important to note that the ACP is not integrated into the LSx module;

instead, it needs to be physically mounted onto the customer's board by ODMs/OEMs. LSx

establishes communication with the ACP using the I2C protocol.

Apple provides another option to use the software ACP instead of hardware ACP but, it has

certain limitation as explained in the below section.

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8.3.1.1. SoftACP

As an alternative to hardware ACP, Apple offers a method for authenticating AirPlay

services using software tokens. In this approach, Apple allocates software tokens and these

to be provisioned to LSx. Provisioning the tokens onto an accessory can be done through either

factory provisioning or in-field provisioning.

1. Factory Provisioning: The tokens can be flashed to LSx during the factory process.

2. In-Field Provisioning: For devices that have previously been manufactured or sold,

in-field provisioning may be used to upgrade them to become AirPlay audio enabled

through a firmware update. To support this Libre/customer can host a server,

install tokens in the server and can be provisioned to LSx on token request during

the initial setup.

However, it's important to consider the following limitations while using software tokens:

1. Incompatibility with WAC: Software tokens do not support Wireless Accessory

Configuration (WAC).

2. Limited Support on Older Apple Devices: Software authentication support was

added in iOS 13.4 and is not supported in earlier versions.

3. Custom Cloud Management: Need to maintain and manage a customized cloud

infrastructure to support token provisioning in case of on-field provisioning.

4. It is mandatory for the end user to add the device to Apple Home APP before using

AirPlay. Apple Home APP reprovisions the device by issuing new tokens.

5. Software authentication requires setup of a bulk vendor server to download the

tokens from Apple. The product manufacturer is expected to come up with their

own mechanism to inject the token in the factory or OTA and Apple does not

provide this infrastructure.

In- field provisioning status info is provided by MB#17.

MB# 17 - SoftACP Status

Description

Provides in-field provisioning status.

HOST MCU

Optional

If token provisioning is not successful, device will not be able to

support AirPlay. APP/HOST MCU UI can display the success/error

status to take appropriate actions.

APP

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8.3.1.2. ACP Factory Tests

As the ACP is not included in LSx module but is down designed into customer’s PCBA, it

becomes crucial to thoroughly inspect the connectivity and soldering quality of the ACP

chipset during factory test phase.

Performing operations like AirPlay playback or WAC setup within the factory can be costly

hence to validate the ACP connectivity, LSx provides MB#14 & MB#15 to read the version

information from the ACP. ODMs/OEMs can employ these MBs to validate ACP connectivity

as part of their factory processes.

Factory Test (MB# 14 & 15 - ACP Share Command & Response)

Description

Used to check the connectivity and solderability of the ACP chipset.

HOST MCU

Optional

In factory, HOST MCU can trigger MB#14 with “MAJOV”, LSx will

communicate with ACP chipset over I2C and receive the major

version from ACP and this will be responded over MB#15.

HOST MCU can check the version and determine whether the ACP is

functional.

APP

Not Applicable.

8.3.1.3. ACP Share

When a product mount multiple LSx modules, the ACP can be shared between these

modules in order to reduce the cost. In this setup, one LSx module takes on the role of a

master and interfaces with the ACP through the I2C protocol.

HOST MCU can manage this by retrieving the required information from the master LSx

(ACP Certificate, ACP Device Version, ACP Firmware Version, etc.) making use of MB#14 &

MB#15 and sharing this info to other LSx slave devices. This approach allows for efficient

sharing of the ACP among multiple modules. Contact Libre FAE for more details.

The NV Item “AcpToLS” is used to set the LSx as master or slave, ODM to set it as per the

design. HOST MCU can identify the master LSx from the schematic design and use this

information to provide the respective LUCI commands.

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MB# 14 &15 - ACP Share Command & Response

Description

Used by HOST MCU to share ACP among multiple LSx modules.

HOST MCU

Optional

LSx slave will request HOST MCU on MB#14 for the required data,

HOST MCU to trigger MB#14 to LSx master.

LSx master to provide the response to HOST MCU over MB#15.

HOST MCU to provide this response back to LSx slave over MB#15.

APP

Not Applicable.

8.3.2. AirPlay Password

To manage access to music streaming through AirPlay, an authentication password can be

implemented. This is entirely optional, but it can ensure that only authorized users can play

music on the device. The user has three options to configure AirPlay password via:

1. Apple Home APP

2. Webpage/APP

3. WAC

Apple Home APP

Apple offers a built-in APP on iOS devices called "Home" that is part of Apple's HomeKit

ecosystem. The Home APP allows users to manage and control their HomeKit-compatible

smart home devices. After a device is added to the Home APP, there is an option to set the

desired password. If a device had a password configured through a webpage, app, HOST

MCU, or WAC prior to its addition to the Home APP, the Home APP will request that specific

password as a prerequisite before including it within the Home APP.

Webpage/APP/HOST MCU UI

For a device that has not yet been added to the Apple Home APP, users should have the

ability to view and edit the friendly name and password. Once a device has been added to

Home, the user must not be allowed to change the name and password via

webpage/APP/HOST MCU UI.

1. The user has the option to configure the AirPlay password either through a mobile

APP or a webpage or HOST MCU UI, however, this can only be done when the device

is not already added to Apple Home APP. If the device is already added in the Apple

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Home APP, the Apple Home APP will take priority and override the password set by

the user through other means.

2. If a device is added to the Home APP and there is no password set for the Home APP.

The password will be empty, but the user will still be unable to set a password via

webpage/APP/HOST MCU UI.

3. In cases where the device is removed from the Home APP, the password will be left

empty, allowing the user to set a new password through the webpage, app, or HOST

MCU UI.

To set a password for AirPlay, it's essential to confirm that the device is added to Apple

Home APP or not. MB# 561 verifies whether the device is added to Apple Home APP, MB#

562 facilitates password setup, and the response is conveyed through MB# 563.

MB# 561 - Apple Home APP Inclusion Check

Description

Used to check if the LSx device is added in Apple Home APP.

HOST MCU

Optional

Applicable only if HOST MCU have a display.

Determines whether friendly name and set AirPlay password fields

are editable and update the UI accordingly.

APP

Optional

Determines whether friendly name and set AirPlay password fields

are editable and update the UI accordingly.

MB# 562 & 563 - AirPlay Password Request & Response

Description

Used to set/get the AirPlay password.

HOST MCU

Optional

Applicable only if HOST MCU have a display.

Set password: Facilitates to set the user entered password.

Get password: Displaying the password might breach the security,

however it can be used to get the password length and show

asterisks.

APP

Optional

Set password: Facilitates to set the user entered password.

Get password: Displaying the password might breach the security,

however it can be used to get the password length and show

asterisks. On the other hand, it can also be used to display the

password for the device in which the password was set originally.

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Status 1

Device Configured

(From MB# 563)

Yes

Status 3

Invalid Message

(From MB# 563)

No

Apple Home APP

Configuration

Validate JSON

Format

Correct JSON Format

Wrong JSON Format

MB# 562

Status 0

Success

(From MB# 563)

Status 2

Invalid Password

(From MB# 563)

No Yes

Validate Password

GET Password

Correct JSON Format

Set New Password

Apple Home APP

Configuration

Yes Status 1

Device Configured

(From MB# 563)

No

Status 0

Share the current

AP2 Password

(From MB# 563)

SET Password

WAC

The user can also set AirPlay password through WAC. The iOS device will display a list of all

compatible devices that are in WAC setup mode. After configuration, the user can change

the device friendly name and set AirPlay password.

1. The user has the option to configure the AirPlay password through WAC only if the

device is not added to Apple Home APP otherwise Apple Home APP will take

priority and override the password set by the user through WAC.

2. The user can change the AirPlay password through webpage/UI/HOST MCU display,

even if the password is already set in WAC.

3. In cases where the device is removed from the Home APP, the password will be

empty, user can set a new password using webpage/APP/HOST MCU UI.

For more details refer to WAC setup section.

8.3.3. AirPlay Certification

It is mandatory for ODMs to seek AirPlay certification if their products are compatible with

AirPlay. Before formal certification, Libre/ODM will perform pre-certification (WAC, ACT

and BCT) testing and make sure that there are no failures. Few samples of the end product

along with pre-cert reports will be send to Apple for certification. Once Apple is satisfied

with the speaker's compliance with AirPlay standards, they will provide certification and

branding rights and the product will be "AirPlay Certified."

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8.4. TCP Tunneling

TCP Tunneling is a unique capability supported by LSx, enabling the HOST MCU to establish

communication with other network devices via LSx. These network devices can include

companion APP or any other device capable of connecting with LSx using TCP. LSx serves

as a tunnel, exclusively forwarding data between the HOST MCU and the network device

without processing it.

Typical use cases of TCP tunneling can be:

• Implement custom features in the mobile APP without direct support of LSx. For

example, the EQ settings like bass or treble controller can be implemented in APP

making use of TCP tunneling to transfer the user settings to HOST MCU.

• Enhance the APP to add any custom features that need interaction with HOST MCU.

• To display the play view information for the sources external to Libre but managed

by HOST MCU.

The HOST MCU and network clients have the flexibility to create their proprietary

communication protocol and engage in data exchange. Using MB#111, the HOST MCU can

direct LSx to initiate a TCP server on a predetermined port number. Network clients can

then connect to LSx over TCP via this designated port number to commence their

communication over MB#112.

Host MCU LSx

UART

Tunnels TCP Data

LSx module offers TCP tunnel to

network clients/APP

Wi-Fi/Ethernet Wireless Access

Point Smart Phone

Laptop

(Network Client)

Wi-Fi

(Network Client)

Wi-Fi/Ethernet

Figure: LUCI TCP Tunneling

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8.4.1. Server Setup

To set up a TCP server on LSx, the HOST MCU is required to specify the port using MB#111

command. It's essential to note that the chosen port number should be greater than 1023,

as ports ranging from 0 to 1023 are reserved for other purposes. If the specified port

number is less than 1024, LSx will respond with an error. Upon successful receipt of

MB#111 command, LSx will initiate a TCP server, making it ready to accept connections

from network clients.

MB# 111 - TCP/IP Tunneling Start

Description

Used by HOST MCU to notify LSx with the port number on which LSx

will start the TCP tunnel server.

HOST MCU

Optional

After bootup and once the system is ready for LUCI communication,

HOST MCU can request LSx over MB#111 to initialize TCP tunneling.

APP

Not Applicable

8.4.2. Communication

Once the server setup is successful, network clients can establish connections with LSx and

initiate communication with the HOST MCU. LSx acts as a tunnel, transmitting data

received from network clients to the HOST MCU through MB#112 command. If the HOST

MCU wishes to send data to the network clients, it can transmit the data to LSx using the

same MB#112 command. Upon receiving the MB#112 command from the HOST MCU, LSx

will distribute the data to all connected network clients.

Important points to consider:

1. LSx can accept a maximum of 2048 bytes of data from network clients in a single

transaction. If the data volume exceeds this limit, it will be fragmented and

forwarded to the HOST MCU. The responsibility for reassembling this data lies with

the HOST MCU.

2. When multiple network clients are simultaneously transmitting data to LSx, LSx will

process this data sequentially in the order it is received. LSx does not provide any

specific information about the source network client. Any identification details or

protocol-specific information should be added by the HOST MCU and network client

as needed.

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3. Data received from the HOST MCU via MB#112 will be broadcast to all network

clients connected to LSx at that moment. There is no provision to target or send data

exclusively to a particular network client.

MB# 112 - Tunnel Data

Description

Used by MCU or LSx to send TCP data.

HOST MCU

Optional

• Forward the TCP data to network clients through LSx.

• Obtain the TCP data sent by network clients from LSx.

APP

Not Applicable

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8.5. OEM App Setup Flow

This section provides a general overview of setting up LSx using the OEM app as part of the

Out of the Box Experience (OOBE). For devices that support Google Cast (GC4A - Google

Cast for Audio), Google imposes specific setup flows and guidelines. In this section, we will

explain the OEM app setup flow mandated by Google. It's strongly advised for ODMs/OEMs

to adhere to the relevant sections, even if Google Cast is not supported on the device.

GC4A 2.0 OEM App Setup

Google has come up with a newer version GC4A 2.0 (aka Cast Lite 2.0) and mandated all

OEMs to go ahead with Cast Lite 2.0 for all products launched post Dec 2023. With the

release of Cast Lite 2.0, the Google Home App will no longer support Wi-Fi setup or Cast

enablement for third-party devices running Google Cast. These responsibilities have moved

to the OEM setup app.

Google has strict guidelines on the setup flow and cast enablement and OEM app has to

comply with the UX wire frames defined by Google. The OEM app developer should refer to

the latest Google CRD and implement the flow as per the guidelines. This section details the

requirements in high level, refer Google guidelines for more details.

8.5.1. Network Configuration

The OEM setup app MUST allow users to choose a Wi-Fi network and input the correct

password to connect to the network. OEM setup apps MUST allow users to select the

configured device and remove or change the Wi-Fi network connection settings. LSx

supports network configuration using BLE, contact Libre FAE for further information and

documentation.

For the devices that do not support Wi-Fi, but only ethernet, this step can be skipped.

8.5.2. Device Friendly Name

LSx provides a default friendly name for each device. The OEM app MUST provide users an

option to switch from the default name to a unique name for their device in the OOBE flow

and MB#90 can be used to facilitate this.

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HOST MCU/APP LSx

MB#90 GET/SET Command

MB#90 SET Response

MB#90 – Device Name

Description

Used to fetch or update the device friendly name.

HOST MCU

Optional

If the product includes a display feature, the HOST MCU can offer users the

choice to view the default friendly name and provide an option to modify it.

APP

Mandatory

As a part of setup flow or from settings menu, the app can offer users the

choice to view the default friendly name and provide an option to modify it.

8.5.3. OTA Update

The LSx setup flow must incorporate a mandatory, non-skippable step to verify the

availability of firmware updates. If an update is available, the process must proceed with

the firmware update. The OEM app must integrate this flow into the setup process. The

OEM app can verify firmware update availability using MB#223. If an update is detected,

the corresponding UI for the entire firmware update process should be displayed, refer the

OTA feature section in the LUCI document for more details. If no update is available, the

process can continue with a notification message stating that the firmware is up to date.

8.5.4. Google ToS and User Feedback

MB#571 and MB#572 facilitate communication between the app and LSx for executing

Terms of Service (ToS) and user feedback. The app will initiate this process immediately

after network configuration and LSx may not have fully booted Google Cast services at that

time. Therefore, the OEM app must verify whether LSx is ready to accept these settings. To

accomplish this, the app should first check MB#7 (Google Cast Version Information). If

Google Cast has booted, MB#7 will provide a valid version number; otherwise, it will return

no data (empty). The app should repeatedly query this message until it receives a valid

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version number to ensure that the Google Cast service is booted before proceeding with the

ToS.

8.5.4.1. Google Terms of Service (ToS)

OEM app MUST provide users an option to accept ToS during the setup flow, after a

network connection has been established. User will have an option to either "Accept" or

"Skip" the ToS. If the user chooses not to accept the ToS, they will be unable to cast audio to

LSx using a Google Cast-enabled app. However, if the user agrees to the ToS, LSx will

activate the necessary settings, which will remain in effect until a factory reset occurs.

8.5.4.2. User Feedback

Enable Usage Reporting Opt-In

If the Google ToS is accepted by the user, the OEM setup app MUST include a page in the

setup flow with a prompt for the user to opt-in to allow Google to collect device data.

Essentially, this entails seeking the user's authorization to submit device status and crash

reports to Google. The user retains the option to either Opt-In or Opt-Out of this feature.

The chosen preference will then be transmitted by the application to LSx. LSx, in turn, will

undertake the appropriate action based on the user's selection, either sending or refraining

from sending the data and crash reports to Google servers.

Opt-In/Opt-Out Settings for Usage Reporting (post OOBE)

Users will also be able to change their usage reporting setting from the Google Home app.

Thus, the OEM setup app MUST read the usage report value from LSx and display it to the

user correctly in the device settings page. This must be provided in the OEM setup app

settings UI under Google Cast menu or something similar. OEM setup app MUST allow

users to Opt-In/Opt-Out of usage reporting post OOBE in the same location.

MB# 571 SET Command

APP LSX

MB# 572 SET Response

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MB# 571 (Google Cast ToS and Usage Report – Requests)

MB# 572 (Google Cast ToS & Usage Report – Response)

Description

Used to read/update user preferences for ToS and usage report.

HOST MCU

Optional

If the product includes a display feature and if customer has

requirements to provide UX for Google Cast enablement from built-

in display, HOST MCU can utilize this MB to read/update the user

preferences for ToS and usage reports.

APP

Mandatory (if the product supports Google Cast)

As a part of setup flow or from settings menu, the app can offer users

the choice to accept/reject the ToS and usage reports.

8.5.4.3. Cast Built-in User Education

The OEM setup app MUST present a brief description of Google Cast, including a link and

direct the user to continue in the Google Home app to set up groups and other Google Cast

features.

8.5.4.4. Deep-link to Google Home App

OEM apps MUST provide the user a prompt to continue onto the Google Home App via a

deep-link after completing setup and accepting Google ToS and accepting (or rejecting)

usage reporting.

8.5.4.5. Time Zone Configuration

The OEM app is required to retrieve the user's selected time zone from the mobile services

and transmit this information to LSx. The application has the flexibility to send this data

without presenting a user interface screen for time zone selection. Alternatively, it may

offer users the choice to select their time zone within the app. Given that mobile services

already furnish the selected time zone, the latter option might be unnecessary.

Additionally, the OEM application can include a feature in its settings menu that allows

users to modify the time zone if needed. MB#573 facilitates this option.

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MB# 573 GET Command

APP LSX

MB# 573 SET Response

MB#573 – TimeZone Configuration

Description

Used to query the timezone settings of the LSx device and to modify

the device timezone using OEM app.

HOST MCU

Optional

If the product includes a display, HOST MCU can utilise this MB to

read/update time zone configurations.

APP

Optional

App can utilise this MB to read/update time zone configurations.

8.6. Firmware Updates

8.6.1. OTA (Over The Air) Update

OTA (Over-The-Air) update is a process of updating a device's firmware or software

remotely, typically through a wireless connection like Wi-Fi.

This section explains the OTA update process and the message boxes involved to share the

status/progress to the HOST MCU & APP.

• OTA update will be performed automatically without user intervention to make sure

the device is always running the updated firmware.

• OTA update process will be initiated:

o After reboot once the device is connected to the network via Wi-Fi or

Ethernet.

o Periodic checks at regular intervals (if LSx is in active playback this update

will be skipped and rescheduled to next periodic check.)

• LSx also provides an option to trigger update manually using MB#238 & MB#235.

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LSx OTA Flow

OTA Manager Check for Update

Signature verification using Libre key

Request for firmware with system

info and Libre certificate

Delete the

downloaded

image

MCU Install

Abort

Application

Cert

Authentication

Push download link

Success

Failure

Success

OTA-Server

SW update

Sig Verification using Libre Key

Application Install

Delete

Downloaded Image

Abort

BSL

Reboot

Update

available?

Yes

No update

available

No

N/A

Download

Reboot

OTA process has four stages:

1. Check for Firmware Update

2. Download the New Firmware

3. Install from Application

4. Install from Bootloader

8.6.1.1. OTA Stages

Check for Firmware Update

LSx will send a request to the server containing the current device information, which

includes hardware details, the current firmware version, and some data from the MCU. The

OTA server will then respond with information about the availability of an updated

firmware version. The status of the update check will be communicated to the HOST

MCU/APP via MB#223.

To ensure accurate reporting to the OTA server, the HOST MCU must inform LSx of its

current firmware version. This allows LSx to present this information to the OTA server

effectively.

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HOST MCU LSX

If update available

or

No update available/

Error in server connection

MB# 6HOST Version (on bootup)

MB# 232 AC power status

(on bootup/change in state)

MB# 223 Update started

or

No update

MB#6 – HOST MCU Version Info

Description

To notify the HOST MCU version to LSx.

HOST MCU

Mandatory

• LSx will send the HOST MCU version information to OTA server to

verify if the HOST MCU is running the latest available firmware.

• HOST MCU must send this info in the bootup process.

APP

Not applicable.

MB#223 – Firmware Upgrade Status

Description

Used by LSx to notify the firmware upgrade state to HOST MCU/APP.

HOST MCU

Mandatory

• To display the firmware upgrade status/progress in UI.

• To do internal actions in HOST MCU for firmware update.

APP

Mandatory (for OOBE)

• To display the firmware upgrade progress in app.

• After the first Wi-Fi configuration (OOBE flow), app can check this

MB for any available update and display the ‘update in progress’

screen.

MB#232 - AC Powered

Description

Used by HOST MCU to notify the power state of product to LSx.

HOST MCU

Mandatory (for battery powered)

• To send the power status on bootup.

• To report the power status upon a change in the power source

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(battery/live power).

• LSx will skip OTA if the device is running in battery power and the

battery level is below a specified threshold.

APP

Not applicable.

Download the New Firmware

If an updated firmware for the device is available in the server, LSx will start downloading

the new firmware. The download status and progress will be shared to MCU/APP via

MB#223.

HOST MCU LSX

MB# 223

"UPDATE_DOWNLOAD"

Download progress <1 - 100>

MB# 223

"UPDATE_IMAGE_AVAILABLE"

"DOWNLOAD_FAIL"

MB# 223 Download Start

Download Progress

Download Complete

Error in Download

or

MB#223 – Firmware Upgrade Status

Description

Used by LSx to notify the download progress to HOST MCU/APP.

HOST MCU

Mandatory

• To display the firmware download progress in UI if there is an MCU

display.

• To do internal actions in HOST MCU for firmware update.

APP

Optional

• To display the firmware download progress in app.

• After the first Wi-Fi configuration (OOBE flow), app can check this

MB for any available update and display the ‘update in progress’

screen.

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Install from Application

If the new firmware is downloaded successfully, LSx will start the installation process.

The first stage of installation will be taken care in the application without reboot. The

following steps will be done in this stage:

• Verify the integrity and authenticity of the downloaded firmware.

• Install the bootloader (BSL) firmware (if available).

• Transfer the MCU firmware to HOST via XModem (if available).

• Reboot to bootloader.

All the installation status will be notified to HOST MCU/APP via MB#66.

HOST MCU LSX

MB# 66

"CRC_CHECK_ERROR"

Install progress

<1 - 70>

MB# 68 <MCU Firmware size>

Xmodem

Transfer

MB# 223 If firmware verification fails

or

Install required components

If MCU firmware available

MCU firmware transfer

MB# 66 Install progress

<80 - 100>Install progress

MB# 66 "complete" Complete stage 1 installation

MB# 114 "rebootrequest" requesting host to reboot

MB# 115 reboot command Graceful shutdown

Reset LSx

During XModem transfer of MCU firmware LSx/HOST MCU must stop all LUCI

communication over UART.

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MB#66 – Firmware Install Progress

Description

Used by LSx to notify the installation progress of new firmware.

HOST MCU

Mandatory

• To display the firmware installation progress in UI.

• To do internal actions in HOST MCU for installation.

APP

Optional

To display the firmware installation progress in UI.

MB#68 – HOST Image Ready

Description

Used by LSx to notify HOST MCU to start the HOST MCU firmware

update process.

HOST MCU

Mandatory

• Stop sending any LUCI communication during MCU update.

• Start Xmodem transfer to receive MCU firmware from LSx.

• After Xmodem transfer completes, resume LUCI communication.

APP

Not applicable.

MB#114 – Reboot Request

Description

Used by LSx to notify the HOST MCU to reboot LSx to complete the

installation.

HOST MCU

Mandatory

• To send MB#115 to enable graceful shutdown of LSx.

• In systems with HOST MCU, LSx will reboot only if HOST MCU does

a hardware reset.

APP

Optional

Can be used to display the UI to notify installation progress.

MB#115 – Reboot Command

Description

HOST MCU to send graceful shutdown request to LSx.

HOST MCU

Mandatory

• To send this after receiving reboot request on MB#114.

• HOST MCU must send this MB to close all the apps running on LSx.

Failure to do so will result in unexpected UI behavior in content

apps.

APP

Not applicable.

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Install from Bootloader

If the stage 1 installation is successful in application, LSx will enter Bootloader mode after

the reboot. LSx will install all the components in the firmware and reboots the new

application firmware. There will be no communication to HOST MCU from LSx in

bootloader. After installation, LSx will automatically reboot to new application and HOST

MCU can wait for MB# 0xAAAA.

8.6.1.2. OTA Trigger

LSx enables OTA updates through MB#235, which can be used by the HOST MCU or APP to

check and update LSx firmware at any point of time as a part of UI/UX. On receiving this

MB, LSx will follow the standard OTA process.

MB#235 – OTA Trigger

Description

This MB allows manual triggering of OTA upgrades from HOST MCU

or app.

HOST MCU

Optional

To manually trigger OTA.

APP

8.6.1.3. Forced Upgrade

LSx provides an option to do force update of the firmware available in the OTA server

without any version check. This can be used to reinstall the same firmware version or older

versions if there is a special requirement.

Force Upgrade is not recommended and is not a part of regular flow, contact

Libre FAE if HOST MCU have a requirement to use this.

MB#238 – Forced Upgrade

Description

This MB facilitates forced OTA upgrades.

HOST MCU

Optional

HOST MCU can reapply a firmware update using the current

firmware available on the OTA server, even if it matches the version

currently running on the device.

This requirement arises from the incorrect installation of the

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previous firmware upgrade on the HOST MCU or DSP module,

attributed to potential bugs or limitations in the HOST MCU/DSP

firmware update implementations.

APP

Not applicable.

8.7. BLE Remote

The BLE Remote is designed to seamlessly control all our LS modules, using Bluetooth Low

Energy (BLE) technology. The HID (Human Interface Devices) protocol offers a

standardized way to transmit user input data from devices such as keyboards, mice and

more, enabling seamless interaction between various devices and systems. This

communication format is universally recognized by all operating systems and our BLE

remote supports the HID protocol.

Our remote operates with the HOGP (Human Interface Over GATT Profile), allowing it to

communicate with and control any compatible device. With nearly 13 buttons, including

the source switch and Bluetooth buttons, the remote simplifies user actions and minimizes

effort. The advantage of this BLE remote is that it enables users to control devices easily

without needing a companion app. Additionally, the remote features an LED that blinks

with each action to notify the user

8.7.1. BLE Remote - Work Flow

The workflow of the BLE remote is detailed below:

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MCU/APP LSX

MB# 663

MB# 664

Data: actioncheck

Check for Feature

Checks Remote feature is

enabled or disabled.

Data: actioncheckstatus

Status: 1 (Enabled), Status: 0 (Disabled)

MB# 663

MB# 664

Data: actionpair

Scan and

connect

User pairs the device

Data: actionpairstatus

Status: 0 (Success), Status: 1 (Failure)

Verifies if the remote feature is enabled or not

Pair the remote

MB# 663

MB# 664

Data: actionunpair

Disconnect and

remove

Data: actionunpairstatus

Status: 0 (Success), Status: 1 (Failure)

Unpair the remote

MB# 663

MB# 664

Data: actionremote status

Fetching remote

status

Data: actionremote statusstatuspairingconnection

Status: 0 (paired/connected), Status: 1 (unpaired/disconnected)

Remote status

User unpairs the

device

Remote status

The app or MCU can determine if the current firmware supports the BLE remote feature by

using the "check" action in JSON format. A status of 0 indicates success, while a non-zero

value denotes failure.

If the feature is enabled, the app or MCU can display the remote's pairing, unpairing and

status information to the user. Based on user actions, the app or MCU will send appropriate

messages to the LSx module via MB# 663, and the LSx module will respond through MB#

664.

Here,

• The JSON format includes two keys: "action" and "status."

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• The "action" key is used by the MCU or app to query the LSx.

• The "status" key is used for the response.

The below table outlines the JSON keys and their corresponding functions used in LSx

systems for managing remote control operations:

Json Key

Info

pair

Initiates scanning and connects the remote to LSx

unpair

Disconnects and unpairs the remote from LSx

check

Verifies if the current firmware supports the remote

remote status

To get remote connection and pairing status

MB#663 - BLE Remote Event Request

MB#664 - BLE Remote Event Response

Description

Used for remote related queries and remote feature controlling.

HOST MCU

Mandatory

• Both the MCU and the app can request the status of the remote

feature to determine whether it is enabled or not.

• Pair/unpair and remote status.

App

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9. LUCI Message Boxes

9.1. Rx_MB# 3 (Register Network Clients)

LS10/11

LS9/X

LS6/5B



APP

MCU



×

This message box is used to register network clients like mobile APPs. It is mandatory for

LUCI network clients to register with LSx as further LSx-APP communication will be

allowed only after successful registration. MB#3 is not applicable for HOST MCU.

LSx has enhanced MB#3 implementation for LS10 and LS11 platforms by including more

client specific information as part of MB#3 registration. All new designs on LS10/11 should

follow this. Refer command <data> section for more details.

APP LSx

MB#3 SET Command

AckMB#3

Acknowledgement

Response

Yes

No

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

3

NA

Variable

Length of

Message

<Data>

Data:

1. Legacy (LS6, LS9, LS10/11 old designs)

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Data values can be IP address, zero or empty. All these data values will result in

successful registration of network client.

2. New Design (LS10/11 designs after October 2023)

Data should be in the below JSON format:

{

"APP_info":{

"id":"<Client ID>",

"version":"<Client Version>",

"ip":"<Client IP address>"

}

Client ID:

• For android APPs, the package name should be used as client ID.

• For iOS APPs, the bundle ID should be used as the client ID.

• For any other network clients, contact Libre FAE.

Client Version: Version of the iOS/android/any network client.

Client IP address: The IP address of the iOS/android/any network client.

e.g.,

{

"APP_info":{

"id":"com.libre.all",

"version":"1.2.3",

"ip":"192.168.1.100"

}

The new design is followed only on LS10 platform. LS10 is backward compatible

with legacy data format to accommodate the APPs that are already designed and in

field. But it is highly recommended to follow new design for upcoming

developments, for existing products, if APP can be enhanced, contact Libre FAE

and take further steps.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

To go back to Feature Section click here.

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9.2. MB# 4 (Deregister Network Clients) - Deprecated

MB#4 is presently inactive across all Libre platforms, as LSx relies on other methods for

client deregistration. The possibility of adding this feature in the future remains open, in

case of any valid use cases.

To go back to Feature Section click here.

9.3. RxTx_MB# 5 (Firmware Version Information)

LS10/11

LS9

LS5B/6



APP

MCU

×



This message box can be used to query the Version Information of LSx speaker. LSx will

send Firmware Version to HOST MCU through the same message box.

HOST MCU LSx

MB#5 GET Command

MB#5 SET Response

Acknowledgement

Response

No

Yes

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

5

NA

Variable

0

-

Response Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

5

NA

Variable

Length of the

data field

<Data>

Data:

Data is the firmware version number.

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9.4. Rx_MB# 6 (HOST MCU Firmware Version)

LS10/11

LS9

LS5B/6



APP

MCU

×



HOST MCU will send the HOST firmware version information in the data field of MB#6 as a

string in numeric format to LSx speaker. This is a default action/command after every

reboot.

HOST MCU LSx

MB#6

SET

ACK

Command

Acknowledgement

Response

Yes

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

6

NA

Variable

Length of data

<Data>

Data:

Data is a numeric value and it varies for each and every firmware.

e.g., “123”

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

To go back to Feature Section click here.

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9.5. Rx_MB# 8 (Serial Number)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



In certain scenarios, customers may want to showcase their unique serial number or device

tag that is printed on the product's label or sticker within a user interface like a webpage or

APP.

To achieve this, HOST MCU can follow any of the below:

• Embed this serial number in its Flash/OTP memory during the HOST MCU's

factory processes.

• Can interact with other customer board MCUs or Flash and fetch the required

serial number.

• Follow any other custom implementation to fetch the serial number.

Once communication with LSx is established through LUCI, during the initial interaction,

the HOST MCU can transmit the serial number or tag to LSx using this message box after

each system bootup. LSx can then store this information and utilize it for various

applications, including webpage displays, as needed.

HOST MCU LSx

MB#8 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

8

NA

Length of data

<Data>

Data:

Data is the serial number/tag provided by the MCU.

e.g.:

LSCST0200000050

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9.6. Rx_MB# 9 (Is HOST Present)

LS10/11

LS9

LS5B/6



APP

MCU

×



This message box is used by the HOST MCU to acknowledge MB#43690.

Upon receiving the message over MB#43690 from LSx, the HOST MCU responds back to

LSx over MB#9 confirming its readiness for further LUCI communication.

This message box is only applicable for LSx-HOST MCU communication.

MB#9 SET Response

HOST MCU LSx

MB#43690 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

9

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

1

HOST is available

To go back to Feature Section click here.

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9.7. Tx_MB# 10 (Playback Authorisation)

LS10/11

LS9

LS5B/6



APP

MCU

×



LSx informs HOST MCU whenever there is a new/change in playback request (AirPlay,

DMR, Spotify, Google CAST, etc.) from any of the music services. HOST MCU then decides if

the new playback source is to be allowed or not. HOST MCU confirms whether the new

source can take over the existing one and responds back in MB#11.

Upon receiving this MB#10, HOST MCU can perform any necessary actions, such as change

the audio route in DSP for LSx playbacks, prepare the DSP with any specific settings like

gain table particular for LSx playback, etc. The HOST MCU can subsequently grant

permission in MB#11 after completing the aforementioned tasks or any other task as

deemed necessary. The actions mentioned are optional and specific to HOST MCU

implementation.

HOST MCU LSx

MB#10 SET Command

MB#11 Response

SET

MB#11 ACK

Acknowledgement

Response

No

Yes, MB# 11

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

10

NA

Variable

Length of the

data field

<Data>

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Data:

Data

LS10/11

LS9

LS6

0

NoSource **

NoSource

1

AirPlay

2

DMR

3

DMP *

DMP

4

Spotify

5

USB

6

Reserved

SDCARD

7

MELON *

MELON

Playlist

8

vTuner *

vTuner

9

TuneIn *

TuneIn

10

Reserved

Miracast

11

Playlist

12

Reserved

DDMSSlaves

13

AuxIn

14

SpdifIn

LineInDDMS

15

Reserved

LineInGeneric

16

Reserved

iPod

17

DirectUrl

18

QPlay

19

Bluetooth

20

Reserved

21

Deezer *

Deezer

22

Tidal

23

Favorites

24

Cast

25

External

26

RTSP *

RTSP

27

Roon

Reserved

28

Alexa

29

Reserved

IoT

Roon

30

Airable

31

Democloud

NA

* These features are not currently implemented but are in the development pipeline.

** NoSource – The data value will read as 'NoSource' if there has been no source played

since the system's bootup. Additionally, if AirPlay was initially chosen as the media

source but is subsequently disconnected and there is currently no active playback

source, the data value will still be 'NoSource.' Presently, this functionality is limited to

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AirPlay, as in other sources, the last connected source will remain displayed even after

disconnection until a new source is connected. Ideally this feature has to be

implemented across all sources, it is in pipeline.

Response Format:

For response, refer to Message Box 11.

To go back to Feature Section click here.

9.8. Rx_MB# 11 (Playback Authorisation Grant)

LS10/11

LS9

LS5B/6



APP

MCU

×



HOST MCU controls and confirms whether the new audio source request received over

MB#10 must be allowed or not.

On receiving MB#10, HOST MCU can parse the current source sent over MB#10 and takes

the decision whether to allow or deny the new playback request. If HOST MCU denies, LSx

will not proceed with the playback.

Though flexibility is provided to deny the LSx playback request based on any precedence,

this may impact user experience and music certifications. Hence, MCU engineers need to

discuss with Libre FAE if they wish to deny the permission for any use case.

After issuing MB#10, LSx will wait for a maximum timeout of ~5-7 seconds (depending on

the platform) for MB#11 response. If HOST MCU does not respond within this timeframe,

LSx will consider the response as denial and won’t be proceeding with the playback. It is

recommended for HOST MCU to respond back in MB#11 as early as possible (50-500ms) to

avoid playback latency.

HOST MCU LSx

MB#10 SET Command

MB#11 Response

SET

MB#11 ACK

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Acknowledgement

Response

Yes

No

Response Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

11

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

0

New audio source not allowed

1

New audio source allowed

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

To go back to Feature Section click here.

9.9. MB# 12 (AirPlay Control) – Deprecated

This feature is specific to AirPlay version 1 and was available for LS6/5B & LS9 devices

until the introduction of AirPlay version 2. Therefore, any customer product on LS6/5B &

LS9 that has not transitioned to AirPlay 2 and still relies on AirPlay 1 will remain

compatible with these commands. Contact Libre FAE in case of any requirements.

9.10. MB#13 (AirPlay Status) – Deprecated

This feature is specific to AirPlay version 1 and was available for LS6/5B & LS9 devices

until the introduction of AirPlay version 2. Therefore, any customer product on LS6/5B &

LS9 that has not transitioned to AirPlay 2 and still relies on AirPlay 1 will remain

compatible with these commands. Contact Libre FAE in case of any requirements.

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9.11. Rx_MB# 14 (ACP Share Command)

LS10/11

LS9

LS5B/6



APP

MCU

×



This message box is used by HOST MCU to send commands to LSx requesting ACP related

data like ACP chip version, ACP certificate, Authentication, etc. LSx responds with the

required data in MB#15.

HOST MCU LSx

MB#14 SET Command

MB#15 SET Response

AckMB#14

Acknowledgement

Response

Yes

Yes, MB# 15

This MB can be used to share ACP with different modules. This is useful in the designs

which incorporates more than one LSx module, so that the LSx module that is interfaced to

ACP act as master and other LSx modules act as slaves. The slave LSx module can request

the required ACP data to HOST MCU via MB#14, HOST MCU request the same to master LSx

using MB#14, master LSx responds with the required data via MB#15 and finally HOST

MCU will send this data back to the slave who requested the data using MB#15.

HOST MCU Slave LSx

MB#14 ACP share Command

MB#15 ACP share Response

Master LSx

MB#14 ACP share Command

MB#15 ACP share Response

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In addition, this MB serves the purpose of factory validation of ACP where HOST MCU can

request the chip version (utilizing the command MAJOV) using MB#14, on this LSx will

communicate with ACP over I2S, fetches the chip version and provides back to HOST MCU.

This whole process flow can be employed during factory process to validate the ACP

solderability and connectivity.

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

14

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

CERTI

ACP Certificate

CHALL, <ACP-Challenge Data>

ACP Challenge Data

DEVVE

ACP Device Version

FIRVE

ACP Firmware Version

MAJOV

ACP Authentication Protocol Major Version

MINOV

ACP Authentication Protocol Minor Version

DEVID

ACP Device ID

For LS10, only the command MAJOV is implemented to validate the ACP

chipset is in place or not.

Currently LS10 supports only ACP version 3.0. and the MB#15 responds as MAJOV,3.

In future, when the ACP version changes, it should be updated to the current version

as it is hard coded now.

Response Format:

For response, refer to MB#15.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format

To go back to Feature Section click here.

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9.12. Tx_MB# 15 (ACP Share Response)

LS10/11

LS9

LS5B/6



APP

MCU

×



Message boxes 14 and 15 work as a pair. Based on the command received by LSx for

MB#14, the response data is sent over MB#15.

Example:

1. Host MCU passes the ‘Challenge’ information over MB#14 to LSx and requests

‘Signature response’. LSx responds back to Host MCU in MB#15, with the data of

‘Signature Response’.

2. Host MCU asks for ‘ACP Device Version’ using MB #14 and LSx responds with ‘ACP

Device Version’ data on MB #15.

HOST MCU LSx

MB#14 SET Command

MB#15 SET Response

ACKMB#14

Acknowledgement

Response

No

Response Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

15

NA

Variable

Length of the

data field

<Data>

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Data:

Command Data

Response Data

Description

CERTI

CERTI, <value>

value is the ACP Certificate

CHALL, <ACP-Challenge

Data>

CHALL, <ACP Signature-

Response>

ACP Signature-Response will contain

the response for the challenge

DEVVE

DEVEE, <ACP Device

Version>

ACP Device Version provides the

device version

FIRVE

FIRVE, <ACP Firmware

Version>

ACP Firmware Version

MAJOV

MAJOV, <ACP Authentication

Protocol Major Version>

ACP Authentication Protocol Major

Version

MINOV

MINOV, <ACP Authentication

Protocol Minor Version>

ACP Authentication Protocol Minor

Version

DEVID

DEVID, <ACP Device ID>

ACP Device ID

ACPNP, <ACP Not Present>

No ACP chip present.

To go back to Feature Section click here.

9.13. Tx_MB# 17 (SoftACP Status)

LS10/11

LS9

LS5B/6

×



×

APP

MCU



Software tokens allocated by Apple must be provisioned to LSx. One of the provisioning

mechanisms is ‘on-field provisioning’ where the tokens will be saved in the Libre/customer

server and will be provisioned in the initial setup. This MB provides the status of

downloading the tokens from the server.

HOST MCU LSx

MB#17 SET Command

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Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

17

NA

Variable

Length of the

data field

<Data>

Data values for Server status:

Data

Description

SERVER_TOKEN_DOWNLOADING

LSx made successful connection with server and a

token is requested.

SERVER_TOKEN_RECEIVE_SUCCESS

If token is downloaded successfully.

SERVER_RECEIVED_WRONG_DEVICE_INFO

Server rejected the token request due to wrong

request data by LSx.

SERVER_SIDE_NO_MORE_TOKEN

When there are no more tokens available in the

server.

To go back to Feature Section click here.

9.14. Rx_MB# 40 (Play Control)

LS10/11

LS9

LS5B/6



APP

MCU



An end user can issue play controls like Play, Pause, Stop, Next, etc. from:

1. Buttons provided in the product (e.g., Play/Pause button), HOST MCU will be

listening and issuing these commands to LSx.

2. Play controls from companion APP.

3. Play controls from content provider APPs.

MB#40 is used to notify LSx with the play control commands issued in cases 1 &2

mentioned above. For case 3, LUCI commands will not be used but LSx will be notified as

per the content provider SDK/protocol.

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HOST MCU LSx

MB#40 Command

MB#40

SET

Ack

Acknowledgement

Response

Yes

No*

* Though there is no specific response, MB#51 will be sequentially sent with the updated

play status.

For MUTE and UNMUTE the response status is sent over MB#63.

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

40

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

PLAY

Start Playback with URL

(Only applicable when device is in a paused/stopped state)

PAUSE

Pause Playback

(Only applicable when the device is currently playing)

STOP

Stop Playback

(Applicable in all states (playing/paused/buffering, etc.)

RESUME

Resume playback after PAUSE

(Only applicable when device is in pause state)

(Only applicable in playing/paused state)

MUTE

Mute playback volume

UNMUTE

Unmute playback volume

SEEK: <time in

milliseconds>

Seek to a location specified by “time in milliseconds.”

(Only applicable when device is in playing/paused state)

REPEAT: <action>

“action” can be ONE, OFF or ALL.

E.g., REPEAT:ONE, REPEAT:OFF, REPEAT:ALL

REPEAT:ONE will loop play back over a song.

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Data

Description

REPEAT:OFF will turn off repeat.

REPEAT:ALL will loop playback over playlist.

If the display has only one icon for all these actions, HOST MCU/APP

has to retain the previous state and notify LSx with the intended

action on pressing the repeat icon.

SHUFFLE: <action>

“action” can be ON or OFF.

e.g., SHUFFLE:ON, SHUFFLE:OFF

SHUFFLE:ON will turn ON shuffle mode

SHUFFLE:OFF will turn OFF shuffle mode

If the display has only one icon for both the actions, HOST MCU/APP

has to retain the previous state and notify LSx with the intended

action on pressing the shuffle icon.

TOGGLEFAV

Toggles favorite state of current song. i.e., it adds or removes the song

from favorite playlist.

REPEATTOGGLE

LSx keeps the REPEAT modes in the order REPEAT:ONE,

REPEAT:OFF and REPEAT:ALL. When triggered by the HOST

MCU/APP using REPEATTOGGLE, LSx transitions between these

REPEAT actions in the order specified.

The repeat toggle behaviour is different in iTunes and in other iOS devices. Repeat

Toggle functionality for different iOS sources should be taken care by HOST MCU.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

To go back to Feature Section click here.

9.15. Rx_MB# 41 (Browse Control)

LS10/11

LS9

LS5B/6



APP

MCU



This MB is used to issue the browse control commands to LSx on user browsing and

playing for the sources for which LSx manages the browsing content. For instance, in USB

playback, LSx directly interacts with the USB pen drive, LSx navigates through the USB

file/folder structure according to the browse controls provided by a user interface such as

a content APP or the HOST MCU display.

Through the companion APP or the HOST MCU display, users have the capability to

navigate USB, DMR, Airable, etc. to select and play songs according to their preferences.

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The HOST MCU/APP issues browse commands via MB#41, prompting LSx to explore the

designated sources and send the browse view via MB#42. Users can continue browsing

until they locate a song or playlist they wish to play. LSx continuously monitors MB#41

control commands, and when it receives a playable content, it proceeds with the playback

accordingly.

HOST MCU LSx

MB#41 Command

MB#41 ACK

SET

MB#42 SET Response

Acknowledgement

Response

Yes

Yes, MB#42

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

41

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

BACK

Goes backward

UP

Navigates up

DOWN

Navigates back

ONETOUCH

The last played track/radio will be played.

SCROLLUP

Scrolls up the page

SCROLLDOWN

Scrolls down the page

SELECTITEM:<index>

Select the particular item at the given index. e.g.,

SELECTITEM:10

SETFAVORITES:<index>

The given track/album/playlist at the index will be saved to

the favorite list. Note that this item is saved in the

respective music services’ cloud.

If HOST MCU provides a button, it can be applicable only for

a track, but in case of APP, it can be a track/album/playlist.

REMOVEFAVORITES:<index>

Remove the track/album/playlist at the given index from

favorites.

ADDTOPLAYLIST:<index>

(Applicable only for Airable).

Add the track at the given index to the selected playlist.

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Data

Description

Here user will select a track, navigate further and selects the

playlist to which it has to be added. LSx will receive this

playlist index through MB#42 and the track will be added to

this selected playlist.

SELECTINFO:<index>

(Applicable only for Airable).

Returns description about selected item at the given index,

device sends the Album/Artist/Track info response in MB#

44.

In Airable UI display, users have an option to access track

info. When a user selects this option, SELECTINFO:<index>

is utilized to retrieve and display the details of the track.

PLNAME:<Name>

(Applicable only for Airable).

When user selects a song and needs to add this to a new

playlist, he needs to first create the playlist, the new playlist

name will be provided in <Name>. On this a new playlist

will be created and the selected song will be added to that.

PAGESELECT:<index>

Jumps directly to the selected page at the given index.

e.g., PAGESELECT:3 will take user directly to 3rd page of the

list.

PLAYITEM: <HTTP URL of

the song>

Play the song from the provided URL.

LSx currently supports playing from a raw URL, this is

called Direct URL playback. For this append ‘DIRECT:’ in the

beginning of the URL of the Song.

e.g., PLAYITEM:DIRECT:<HTTP URL of the song >

This can be extended in future to play URLs from specific

services rather than ‘DIRECT:’

GETUI: <Current view>

To get the required ‘view’ from the HOST MCU/APP.

For Play view, HOST MCU/APP should send command

GETUI:PLAY, for this LSx will provide the play view as

response in MB#42.

For Home view, HOST MCU/APP should send command

GETUI:HOME, for this LSx will send the browse view of the

home in MB#42. Home is the parent directory of the

browsable music sources (it displays USB, Airable, media

server, etc.)

Response Format:

For response, refer to Message Box 42.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

To go back to Feature Section click here.

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9.16. Tx_MB# 42 (UI Info)

LS10/11

LS9

LS5B/6



APP

MCU



This message box is used by LSx to send the Play View/Browse View contents to the HOST

MCU/APP which can be used for display. The UI information is embedded in JSON format.

At present LSx supports only two views: Play view and Browse view. The concept of UI Info

can be extended to cater future requirements adding more views.

Play View: It provides all relevant information for HOST MCU display or companion APP

display to update its play view UI. LSx provides play view JSON at the onset of every

playback. Play View is also provided by MB#45. Refer to MB#45 for more details.

Browse View: It provides all relevant information to populate the browse view for HOST

MCU display or content APP display. This is applicable only for the sources like USB

playback, DMR, Airable, etc. that will request LSx to browse and present the contents. HOST

MCU/APP will provide the browse commands over MB#41 and the response of that is

provided in MB#42. As browse and play are mutually exclusive, MB#42 is used as a

common message box to present both these data.

Steps involved in playing an LSx supported browsable content:

Step 1. User browses the contents (USB, Airable, DMR, etc.) using companion APP or

HOST display.

Step 2. HOST MCU/APP provides browse commands over MB#41.

Step 3. LSx browses the respective sources and presents the browse view over

MB#42 browse view.

Step 4. User selects the final song file and try to play it.

Step 5. LSx initiates the playback and presents the play view information over

MB#42 play view.

LSx will send this message box (both play view and browse view) to HOST MCU only if the NV-

Item HOSTUiEnabled is set to 1. For products which have display and intends to show the UI

information, ensure that the NV-Item is enabled in LSx firmware release package.

HOSTUiEnabled does not control this message box notification to companion APP.

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Step 6. User goes back, continue to browse other contents, provides browse control

over MB#41 and LSx provides browse view over MB#42.

Step 7. …

HOST MCU/APP LSx

MB#41 Command

MB#41 Ack

SET

MB#42 SET Response

Steps involved in playing other content (non LSx browsable content):

Step 1. User initiates and play other contents like AirPlay, CAST, Spotify from

content APPs or any other means like presets from buttons.

Step 2. LSx initiates the playback and provides play view JSON over MB#42 play

view. Note that browse view is not applicable in this case as LSx is not involved in

browsing these contents.

HOST MCU/APP LSx

MB#42 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

42

NA

Variable

Length of the

data field

<Data >

Data:

Data is browse view or play view UI Information in JSON format.

Example for Browse view data played for Airable source:

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Example for Play view data for Airable Source:

For more details, refer to the document Airable UI Guide for

MCU/Companion APP Implementation.

Reading the UI Information

If HOST MCU or companion APP needs to repopulate the display, in scenarios like

navigating to a different screen and returning to browse view/play view or closing and

opening of an APP, etc. they can read MB#42.

To go back to Feature Section click here.

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9.17. Tx_MB# 43 (Artwork Metadata)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



Album art, also known as album artwork or cover art, refers to the visual representation or

graphic design associated with a music album. Album art typically includes an image or

illustration on the album cover, along with the album's title, the artist's name, and often

other information like track listings, record label and release date.

This Message box is used to send the album art information to the HOST MCU enabling it to

refresh its display with the relevant information. This is not applicable for mobile APP as

they will directly fetch the album art from the album art URL provided in metadata.

LSx retrieves the album art information from the music source (whichever supports this)

or fetches the album art from the music file. (e.g., music files in USB storage) and provides

this data to HOST MCU. For music sources/files that does not provide the album art URL

like USB playback, bluetooth, etc. LSx can get album art from meta data provider services

like Gracenote. Gracenote is not implemented in all platforms as it involves commercials,

please discuss with Libre FAE for more details.

LSx stores the album art in JPEG or PNG formats. LSx implements the below two

mechanisms to transfer album art:

1. Over USB interface: Using USB is the preferred method due to its ability to facilitate

faster data transfer, which is particularly advantageous when dealing with large

album art images.

2. Over UART (LUCI): This can be used for small display sizes and for MCUs that

doesn’t support USB. This will result in slow data transfer and also blocks the other

LUCI communication over UART during the transfer time. Libre doesn’t recommend

this method due to its demerits.

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USB Method

LSx will fetch album art from the URL provided by the music services.

LSx resizes the image according to the HOST MCU display size. HOST MCU provides the

display size in the ENV ‘DisplayArtworkSize’.

LSx implements USB HOST and HOST MCU needs to implement USB device (mass storage),

LSx detects this mass storage device, validates the vendor ID and writes the resized image

to HOST MCU over USB.

MCU developer can contact Libre FAE for more details on the USB device mass storage

implementation.

LSx notifies HOST MCU over MB#43 with the details of the album art ready to be

transferred and then starts sending the album art over USB.

On receiving MB#43, HOST MCU can start reading the album art that is being transferred

by LSx over USB interface. HOST MCU can validate the read bytes with “file size” updated in

MB#43 and then update the display.

HOST MCU LSx

MB#43 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

43

NA

Variable

Length of the

data field

<Data>

Data:

Data will be sent in JSON format as given below:

{"response":{"status":"<status type>","filesize":<size>,"service":"<service type>"}}

status type: success or failed.

Failed will be triggered in instances where, LSx could not fetch the album art, e.g.,

the music source does not support album art.

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size: size of the file in bytes

service type: native or Gracenote

native stands for LSx downloading the album art from the URL provided by the

music service/music file. Gracenote is an external paid service that will fetch album

art of the particular music file by providing few essential information about it.

Success status example: {"response":{"status":"success","filesize":7256,"service":"native"}}

Failed status example: {"response":{"status":"failed","filesize":0}}

UART Method

LSx will transmit album art data in chunks to the HOST MCU via UART. Upon the receipt of

each packet, the HOST MCU should send an acknowledgment. Upon receiving the

acknowledgment, LSx will move forward to transmit the next packet, otherwise it will

resend the same chunk.

HOST MCU LSx

MB#43 SET Command

Chunk 1

MB#43 SET Cover Art ACK

MB#43 SET Command

Chunk 2

MB#43 SET Cover Art ACK

MB#43 SET Command

Chunk 3

MB#43 SET Command

Chunk 3

MB#43 SET Cover Art ACK

Acknowledgement

Response

No

Yes

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Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

43

NA

Variable

Length of the

data field

<Data>

Data:

Data will be sent as chunks of information in the format given below:

{<format>, <offset>, <total size>, <data size>, <chunk no>, <chunk data>}

format: Format of the image

offset: Offset of current chunk

total_size: Total size of image

data_size: Size of the current chunk

chunk_no: Chunk number

chunk data: Binary data of the chunk

Example:

1st packet:

format:PNG,offset:0,total_size:69755,data_size:4096,chunk_no:0,�PNG

2nd packet:

format:PNG,offset:4096,total_size:69755,data_size:4096,chunk_no:1,BCPCc2FA�:}��o}

��n��!F�!Y��-7��|��-�O�H]�8kɬ!j�^��

Last packet:

format:PNG,offset:69632,total_size:69755,data_size:123,chunk_no:17,\�l���?

<^-( ܖ +��l�{X�-�m

��l+�m



MCU should read the data and exclude the headers from the image and then store it on the

MCU’s RAM or flash memory for display.

To go back to Feature Section click here.

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9.18. Tx_MB# 44 (Airable Track Info)

LS10/11

LS9

LS5B/6



×

APP

MCU



This MB supports only Airable sources.

HOST MCU/APP can request info about Album/Artist/Track for Airable sources through

MB#41 and the respective details will be sent over in MB#44 by LSx.

HOST MCU/APP LSx

MB#41 SET Command (SELECTINFO:<index>)

MB#41 Ack

MB#44 SET Response

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

44

NA

Variable

Length of the

data field

<Data>

Data:

Data will be sent in JSON format in the below format:

"{"description":"< Info >"}

Info will be the Album/Artist/Track details.

Example:

To go back to Feature Section click here.

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9.19. Tx_MB# 45 (Play View)

LS10/11

LS9

LS5B/6



APP

MCU



Although MB#42 has provided the Play View UI information, there are scenarios where

these are overwritten by the browse view UI contents. For example, user starts browsing

while a playback is ongoing. At this time, if HOST MCU/APP needs play view information

they can depend on MB#45 to GET the play view UI information.

In addition, on start of every playback LSx will provide play view UI information in MB#45.

Hence, this message box serves two purposes:

1. Retrieve the Play view contents

In this scenario, the APP/HOST MCU uses a “GET” command type to fetch the current play

view UI information. E.g., If an APP is opened while a playback is ongoing, APP can use

MB#45 GET to retrieve the play view information.

HOST MCU LSx

MB#45 GET Command

MB#45 SET Response

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

45

0

NA

Variable

-

Response Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

45

0

NA

Variable

<Data>

Data:

Data is UI information in JSON format.

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2. LSx sets the play view data on Playback start

When the user clicks on Next/Previous, Pause/Play or do source switch from current to a

different source, LSx send MB#45 to HOST MCU/APP.

HOST MCU/APP LSx

MB#45 SET Command

This message box is updated with the Play View information. Mobile APPs can read this

message box to update the current song information on ‘Now Playing’ screen irrespective

of device’s current menu/view. The UI information is embedded in JSON format.

This message box keeps only the now playing track/stations information to avoid losing

the playing information when the user browses different contents/menu from the UI.

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

45

0

N/A

Variable

<Data >

Data:

Data is UI information in JSON format.

E.g.:

To go back to Feature Section click here.

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9.20. Tx_MB# 49 (Current Playback Position Time)

LS10/11

LS9

LS5B/6



×

APP

MCU



In every one second, LSx periodically notifies HOST MCU/APP with the current playback

position time of the music being played. The “current playback position time” represents

the elapsed duration of the song in milliseconds.

This information is useful for HOST MCU/APP to show the song progress bar duration in its

display.

HOST MCU LSx

MB#49 CommandSET

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

49

NA

Variable

Length of the

data field

<Data>

Data:

Data will be the current playback position time in milliseconds.

E.g., Suppose LSx is playing a song and if it is currently presenting 2 minutes 15 seconds of

the song, the data will be 135000 milliseconds.

To go back to Feature Section click here.

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9.21. Tx_MB# 50 (Current Source)

LS10/11

LS9

LS5B/6



APP

MCU



This message box is used by LSx to notify the HOST MCU/APP about the currently selected

audio source for playback.

The current playing source information can be used by HOST MCU/APP to display the

playback source details like logo, or any other information.

HOST MCU LSx

MB#50 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

50

NA

Variable

Length of the

data field

<Data>

Data:

Data

LS10/11

LS9

LS6

0

NoSource **

NoSource

1

AirPlay

2

DMR

3

DMP *

DMP

4

Spotify

5

USB

6

Reserved

SDCARD

7

MELON *

MELON

Playlist

8

vTuner *

vTuner

9

TuneIn *

TuneIn

10

Reserved

Miracast

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Data

LS10/11

LS9

LS6

11

Playlist

12

Reserved

DDMSSlaves

13

AuxIn

14

SpdifIn

LineInDDMS

15

Reserved

LineInGeneric

16

Reserved

iPod

17

DirectUrl

18

QPlay

19

Bluetooth

20

Reserved

21

Deezer *

Deezer

22

Tidal

23

Favorites

24

Cast

Reserved

25

External

26

RTSP *

RTSP

27

Roon

Reserved

28

Alexa

29

Reserved

IoT

Roon

30

Airable

31

Democloud

NA

* These features are not currently implemented but are in the development

pipeline.

** NoSource – The data value will read as 'NoSource' if there has been no source played

since the system's bootup. Additionally, if AirPlay was initially chosen as the media

source but is subsequently disconnected and there is currently no active playback

source, the data value will still be 'NoSource.' Presently, this functionality is limited to

AirPlay, as in other sources, the last connected source will remain displayed even after

disconnection until a new source is connected. Ideally this feature has to be

implemented across all sources, it is in pipeline.

The HOST MCU/APP can also read this message box to determine the audio source selected

by LSx using a ‘GET’ command.

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HOST MCU LSx

MB#50 GET Command

MB#50 SET Response

Acknowledgement

Response

No

Yes

Command Format:

Remote ID

Command

Type

Message

-Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

50

NA

Variable

0

-

Response Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

50

NA

Variable

Length of the

data field

<Data>

Data:

Data values are same as mentioned above.

To go back to Feature Section click here.

9.22. Tx_MB# 51 (Current Play State)

LS10/11

LS9

LS5B/6



APP

MCU



This MB is used by LSx to update the HOST MCU/APP on the current play state of LSx.

Whenever there is a change in current play state, LSx communicates it to HOST MCU/APP

over MB#51.

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HOST MCU LSx

MB#51 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

51

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

0

Playing

1

Stopped

2

Paused

3

Connecting

4

Receiving

5

Buffering

Supported Music

Playback Status

Playing

Stopped

Paused

Connecting

Receiving

Buffering

AirPlay

iMusic



(Play)

 (Disconnect/

Source Switch to

AirPlay)



(Source

Switch)

×

Spotify Connect



(Play)

 (Disconnect/

Source Switch)



(Source

Switch)

×

Tidal Connect



(Play)

 (Disconnect/

Source Switch)



×

Cast sources



(Play)



(Disconnect)



×



(Connecting

and

Next/Prev/

Source

Switch)

Amazon Alexa



(Play)



(Pause/Next/Prev

/ Source Switch)



(Next/Prev/

Source Switch)

×

Airable



(Source Switch)



×

Bluetooth



(PAIR and



(AUX source

×

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Supported Music

Playback Status

Playing

Stopped

Paused

Connecting

Receiving

Buffering

UNPAIR)

while AirPlay

to BT switch)

Aux-In



(Change the

source from

the device

button e.g.:

AUX)



(Change the

source from the

device button e.g.:

Wi-Fi)

×

DMR



(Play)



(Next/Prev/

Source Switch)



×

USB



(Play)



(Play)



(Play)

×

Roon Ready



(Play)



(Connecting/

Next/Prev)



(Source

Switch)

×

To go back to Feature Section click here.

9.23. Tx_MB# 54 (Playback Error Status)

LS10/11

LS9

LS5B/6

×



APP

MCU



MB 54 is used to determine whether the playback control events (Pause/Resume,

Next/Previous, Repeat/Shuffle) are success or failure.

LSx sends the Success or Error notification on playback event. This notification is directly

derived from the media player response.

HOST MCU LSx

MB#54 SET Command

Acknowledgement

Response

No

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Command Format:

Remote

ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

54

NA

Variable

Length of

data field

<Data>

Data:

Data

Description

success

When playback succeeds

error_playfail

When the song has bad header and this song is at the last

position in the playlist.

error_nonextsong

Indicates no next song or end of playlist.

error_noprevsong

Indicates no previous song.

error_notsupported

This error message is sent when the given command is not

supported.

error_notavailablenow

onSpotifyfree

Indicates that requested feature is not available for Spotify free

users. (Spotify supports maximum of 6 ‘skip next’ requests in 1

hour for free user. If free user tries to skip 7th song, Spotify

returns error).

error_notsupportedonS

potifyfree

Indicates that invoked action is not supported for Spotify free

users. (Skip back and Seek functions are not available/allowed

for free users).

error_shuffleoffnotsup

portedonSpotifyfree

Indicates that Spotify free user cannot turn off Shuffle. (For free

users, songs always play in Shuffle ON mode).

SpotifyAdsplaying

Indicates that AD is playing on Spotify. (Some user actions like,

next, prev, seek are not supported while playing AD).

To go back to Feature Section click here.

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9.24. Tx_MB# 56 (ISBROWSESTATUS)

LS10/11

LS9

LS5B/6



×

APP

MCU



This MB is used to display browsing error screen in the APP/MCU display in instances

where Airable server experiences downtime or Airable music source is unavailable.

HOST MCU LSx

MB#56 SET Command

Acknowledgement

Response

No

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

56

NA

Length of

the data

<Data>

Data:

The data will be sent in the below format:

Mar 27 11:25:11:462437 I/luci_service[330]: lucitransport: writeRemoteMessage() MID = 56 <Error

Message>

Mar 27 11:25:11:462534 I/luci_service[330]: lucinetwork: write() Command = 56 type = 2 status = 0

len = 21 sockets = 1 ID = 0

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<Error Message> can be any of the following:

Description

buffer = Internal_Server_Error

Server error

Error_Redirection

When the playback fails to redirect to the intended page.

Error_missing_url_secret

When base URL or secret is not available

9.25. Tx_MB# 63 (Remote Source MUTE/UNMUTE)

LS10/11

LS9

LS5B/6



APP

MCU



User can perform audio mute/unmute in two ways:

1. Pressing the mute/unmute button provided by the HOST MCU.

2. Clicking the mute/unmute button provided by the companion APP/content provider

APP (Roon, Google Cast, …). Note that this functionality is not provided by all the

content provider APPs.

This message box sends the mute/unmute status to the HOST MCU when user

mutes/unmutes using the companion APP/content provider APP. On this message, HOST

MCU can mute the audio by controlling the audio DSP/Amp.

In addition, when the user presses the mute/unmute button, HOST MCU will send the mute

state over MB# 40, and LSx will send the response mute/unmute status over MB# 63.

MB# 63 status can be used by HOST MCU to SET mute/unmute status LED.

Mute/unmute from APP:

HOST MCU LSx

MB#63 Mute/Unmute

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Mute/unmute using button:

HOST MCU LSx

MB#63 SET Response

MB#40 SET Command (only for Mute/Unmute)

MB #40 ACK

Acknowledgement

Response

No

Command/Response Format:

Remote ID

Command

Type

Message

-Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

63

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

MUTE

Sends ‘Mute’ state to HOST MCU

UNMUTE

Sends ‘Unmute’ state to HOST MCU

To go back to Feature Section click here.

9.26. Rx_Tx_MB# 64 (Volume Control)

LS10/11

LS9

LS5B/6



APP

MCU



This message box serves the purpose of informing LSx, HOST MCU, or the companion APP

about changes in volume. LSx maintains a volume range from "0," representing no volume,

to "100," which corresponds to the maximum volume.

End users have several methods to adjust the volume:

1. Use buttons/volume knobs or a remote controller to change the volume. In these

cases, the HOST MCU will send a notification to LSx using MB#64.

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2. Users can also make volume adjustments through a companion APP. In this case, the

companion APP will notify the volume changes to LSx through MB#64.

3. When volume changes are made from content provider APPs, the APP will notify LSx

using custom protocols/APIs.

LSx does not feature software-based volume control. Instead, it relies on the HOST MCU to

regulate volume by modifying the gain of the AMP/DSP/CODEC. Upon receiving a

notification of volume change, LSx will undertake the required actions and subsequently

instruct the HOST MCU to execute the actual volume change.

Volume Change trigger from HOST MCU

When the user regulates the volume using buttons or by a remote controller, volume

change takes place, HOST MCU manages this change and subsequently notifies LSx over

MB#64. HOST MCU needs to make sure that the volume level sent to LSx is always in the

range of “0 - 100”.

The procedures undertaken when adjusting the volume on the HOST MCU side are outlined

as follows:

Step 1. The user presses the volume button/remote in the end product.

Step 2. HOST MCU sends the volume control command (value “0 - 100”) to LSx.

Step 3. LSx processes this volume change request and communicate the altered

volume level to the active content providers.

Step 4. LSx sends the volume control command back to HOST MCU and upon this

HOST MCU to regulate the actual volume. LSx also sends the changed volume to

companion APP for updating its UI.

After the volume reaches zero (0) or hundred (100), HOST MCU should inform the

volume changes to LSx module ONLY once. It is advisable for the HOST MCU to avoid

sending continuous successive signals of volume level ‘0’ or volume level '100' to the

LSx module repeatedly.

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HOST MCU LSx

MB#64 SET Response

MB#64 SET Command

MB#64 ACK

Acknowledgement

Response

Yes

HOST-MCU LSx Content Provider App Companion App

User Changes Volume

(Vol + /Vol -) Sends request Over MB# 64

Volume level (0 – 100)

Process Volume

Change Request

Uses Respective Protocol to

Inform Content Providers

Updates Over MB# 64

Volume level (0 – 100)

Updates Over MB# 64

Volume level (0 – 100)

Process Volume

Change

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

64

NA

Variable

Length of the

data field

<Data>

Data:

Data is ‘Volume Level’ values which are always between “0 - 100.”

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Response Format:

Remote ID

Command

Type

Message

-Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

64

NA

Variable

Length of the

data field

<Data>

Data:

Data is ‘Volume Level’ values which are always between “0 - 100.”

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

Volume Change through Companion APP

When user changes the volume using companion APP, it notifies LSx using MB#64, LSx

process these changes and notify HOST MCU to regulate the actual volume as per the levels

provided in MB#64.

Step 1. The user changes the volume in the companion APP.

Step 2. Companion APP notifies LSx regarding the volume change via MB#64, LSx

processes this volume change request and updates active content providers.

Step 3. LSx sends the volume control command (value between “0 - 100”) to HOST

MCU via MB#64. HOST MCU to regulate the volume. LSx also sends the changed

volume to companion APP for updating its UI.

HOST MCU LSx

MB#64 SET Command

APP

Acknowledgement

Response

No

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HOST-MCU LSx Content Provider App Companion App

Process Volume

Change Request

Uses Respective Protocol to

Inform Content Providers

Updates Over MB# 64

Volume level (0 – 100)

Updates Over MB# 64

Volume level (0 – 100)

Process Volume

Change

User Changes Volume

Volume level (0-100)

Volume change through Companion APP

Volume Change through Content Provider APPs

When user changes the volume using content provider APP, it notifies LSx using MB#64,

LSx process these changes and notify HOST MCU to regulate the actual volume as per the

levels provided in MB#64

The procedures undertaken when adjusting the volume on the LSx side are outlined as

follows:

• The user changes the volume in the content provider APP.

• Content provider APP notifies LSx regarding the volume change via MB#64,

LSx processes this volume change request.

• LSx sends the volume control command (value between “0 - 100”) to HOST

MCU via MB#64. HOST MCU to regulate the volume.

HOST MCU/

Companion App LSx

Volume Level

MB#64 SET Command

Content Provider

APP

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HOST-MCU LSx Content Provider App Companion App

Process Volume

Change Request

Updates Over MB# 64

Volume level (0 – 100)

Updates Over MB# 64

Volume level (0 – 100)

Process Volume

Change

User Changes Volume

Volume change through Content Provider APP

Reading Current Volume Level

HOST MCU/APP can GET the volume level from LSx using MB#64 at any point of time.

HOST MCU LSx

MB#64 GET Command

MB#64 SET Response

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

64

NA

Variable

0

--

Response Format:

Remote

ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

64

NA

Variable

Length of Data

Field

<Data>

Data:

Data is ‘Volume Level’ values which are always between “0-100.”

To go back to Feature Section click here.

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9.27. Rx_ MB# 65 (Firmware Request) - Deprecated

HOST MCU triggers LSx module to initiate firmware upgrade process.

9.28. Tx_MB# 66 (Firmware Install Progress)

LS10/11

LS9

LS5B/6



APP

MCU



This MB is used to indicate the installation progress of the LSx firmware to HOST

MCU/APP.

HOST MCU LSx

MB#66 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

66

NA

Variable

Length of data

field

<Data>

Data:

Data

Description

0 to 100

Percentage progress varying from 0 to 100 (multiples of 10).

E.g.: 10%, 20%, 40%, 60%, 80%, …100%

Complete

LSx sends the data as ‘Complete’ on successful upgrade.

To go back to Feature Section click here.

LUCI Technical Note

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9.29. Tx_MB# 68 (HOST Image Ready)

LS10/11

LS9

LS5B/6



APP

MCU



This message box is used by LSx to inform the HOST MCU on the availability of a HOST MCU

Image ready for firmware update. After receiving this MB, the HOST MCU should start the

xModem transfer.

HOST MCU LSx

MB#68 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

68

NA

Variable

Length of the

data field

<Data>

Data:

Data will be the size of the MCU image in bytes.

To go back to Feature Section click here.

9.30. MB# 69 (Request Firmware Upgrade) - Deprecated

This MB is used only in LS6 module to request permission for Firmware Upgrade from

HOST MCU. On Firmware Upgrade trigger, LSx sends firmware upgrade request to HOST

MCU and waits for a response from MB# 211.

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9.31. RxTx_MB# 70 (Preset, Auto USB & Standby)

LS10/11

LS9

LS5B/6



APP

MCU



This message box is employed to manage the favorite/preset feature and auto playback

(USB). The HOST MCU can add the presently playing song to the favorites list by assigning

it a specific index. Later, it can play this song using the assigned index number, delete it, or

view the list of songs in the favorites. Preset is applicable for the sources such as Spotify,

Airable and UPnP.

Moreover, this message box is also utilized for USB auto playback, especially in cases where

there is a dedicated USB playback button. Note that that USB auto playback will be moved

to MB#76 in future designs.

Furthermore, this message box serves to inform LSx about the device's standby status

(ON/OFF) so that it can initiate the necessary actions accordingly. When a user presses the

standby button, the HOST MCU will use this message box to notify LSx of the corresponding

standby state. Additionally, there are options to enable or disable device standby from

content applications like ROON. In such instances, LSx utilizes this message box to notify

the HOST MCU about the standby state.

HOST MCU LSx

MB#70 SET Command

MB#70 SET Response

Acknowledgement

Response

No

Yes

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

70

NA

Variable

Length of data

field

<Data>

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Data:

Data

Description

PLAYUSB

Using this command, the HOST MCU/APP can start USB Playback, and

when the command is executed successfully, the device will begin USB

playback. This is useful in scenarios where HOST MCU dedicates a

button for USB playback.

FAV_SAVE: <Index>

HOST MCU/APP sends the command to save the current playing song in

the specified favorite/preset location. Index range is from 0-9.

E.g., To save the current playing song in location 5 of the Favourite list,

HOST MCU sends the command as FAV_SAVE:5.

Note: The index range for LS10/11 is increased to 0-19.

FAV_PLAY: <Index>

HOST MCU/APP sends command to play the song specified in index

location from the favorite/preset list.

E.g., To play the song in location 5 of the Favourite list, HOST MCU

sends the command as FAV_PLAY:5.

FAV_DELETE:<Index>

HOST MCU/APP sends command to delete the song specified in index

location from the favorite list.

E.g., To delete the song in location 5 of the Favourite list, HOST MCU

sends the command as FAV_DELETE:5.

FAV_LIST

HOST MCU/APP sends command to receive the songs saved in favorite

list.

On successful execution of the command, LSx device sends the stored

list of songs in JSON format.

STANDBYON

To notify standby ON state to LSx from HOST MCU.

To notify standby ON state to HOST MCU from LSx. (Trigger from

content provider APP)

STANDBYOFF

To notify standby OFF state to LSx from HOST MCU.

To notify standby OFF state to HOST MCU from LSx. (Trigger from

content provider APP)

Response Format:

Remote

ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

70

SUCCESS /

FAILURE

Variable

Length of

data

<Data>

Data for PLAYUSB:

In case of successful execution of the command, device starts USB playback.

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LSx sends the following response to HOST MCU in case of playback failure.

Data

Description

NO_USB

USB device is not connected/detected on the LSx device.

NO_SONG

No audio file available in the USB device.

Data for Standby

No response.

Data for FAV_SAVE: <Index>:

Data

Description

GENERIC_FAV_SAVE_SUCCESS

Successfully saved the favorite list.

GENERIC_FAV_SAVE_FAIL

Failed to save the favorite list.

GENERIC_FAV_EXISTS

The song already exists in the favorite list.

Data for FAV_PLAY: <Index>:

Data

Description

GENERIC_FAV_PLAY_SUCCESS

Upon successful playback of the favorite track.

GENERIC_FAV_PLAY_FAIL

When playback fails due to server being not

reachable/not found.

GENERIC_FAV_PLAY_NOURL

URL for playback is not found in the favorite list.

Data for FAV_DELETE:<Index>:

Data

Description

GENERIC_FAV_DELETE_SUCCESS

Successfully deleted the favorite track.

GENERIC_FAV_ DELETE _FAIL

Failed to delete the favorite track from ENV item.

Data for FAV_LIST: On successful execution of the command, LSx device sends the stored

favorite songs list in JSON format as response. If there is no favorite list, the response will

be empty.

For example,

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JSON names in LS10/11 are changed from LS9 to reduce JSON size.

LS9

LS10/11

PresetName →

Name

PresetIndex →

Index

PresetURL →

URL

To go back to Feature Section click here.

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9.32. Rx_MB# 76 (Acquire & Play)

LS10/11

LS9

LS5B/6



APP

MCU

×



This MB is used by HOST MCU/APP to trigger playback from a specified source. For

example, if there is dedicated buttons to play USB, on pressing that button, HOST MCU/APP

will trigger this MB, on that LSx can start the playback from the specified source. This MB

can be extended for all required sources, currently supported sources are:

1. Spotify

2. USB Playback (To Do – This is still handled in MB#70, will be moved to MB#76)

HOST MCU LSx

MB#76 SET Command

Acknowledgement

Response

No

Spotify Grab

By pressing a specific button or selecting the Spotify source through the display interface,

this feature permits the continuation of Spotify playback from its previous state, provided

that Spotify has been played at least once prior. It's important to emphasize that this is a

mandatory certification requirement imposed by Spotify.

Spotify Certification Checklist:

Test No.: 10.6

Test Case: Pull Context

Description: Press play on the DUT

Expectation: Spotify should start playing from where the user left it off.

Command Format:

Remote

ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

76

SUCCESS /

FAILURE

Variable

Length of

Data

<Data>

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Data:

Data

Description

GRAB

Switch source to Spotify, start the playback

SPOTIFY GRAB

Not yet implemented

USB GRAB

Not yet implemented

To go back to Feature Section click here.

9.33. RxTx_MB# 80 (Play Audio Cues)

LS10/11

LS9

LS5B/6



APP

MCU

×



This message box is used to play custom audio cues for any event notifications as per the

customer requirements. Distinct tones can be assigned for each event notification based on

customer preferences, such as a unique tone for successful Wi-Fi connectivity or another

for indicating successful bluetooth pairing and so on. These tones have to be renamed as

“song<x>.file type” (Note: LS9 supports all formats and LS10 supports only .wav) where x can

be values from 1-10, a maximum of 10 such tones can be supported. Using the software

customisation kit (SCK) these files can be included in the final LSx firmware package. LSx

will store these files in a predetermined location in device flash. This can be played by the

HOST MCU whenever required using MB#80. It's important to use brief notification tones

to avoid any potential storage space issues. For additional information, get in touch with

Libre's Field application Engineer (FAE).

HOST MCU LS

MB#80 SET Command

MB# 80 SET Response

Acknowledgement

Response

No

Yes

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Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

80

NA

variable

length of

data field

<Data>

Data:

Data format is as given below:

play <Index>

Supported Index values are 1-10.

E.g.: play 3

On this LSx will fetch song3.mp3 from flash and play it.

Response Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

80

success/

failure

Variable

Length of

data field

<Data>

Data:

Data

Description

SUCCESS

When the audio cue is correctly played on the device.

FILE_NOT_FOUND

When the audio file is not found in the LSx fw.

NI

When wrong play index or command is given by the MCU.

To go back to Feature Section click here.

9.34. RxTx_MB# 90 (Device Name)

LS10/11

LS9

LS5B/6



×

App

MCU



This MB is utilised by HOST MCU/app to read and update the device name.

Device name or friendly name serves as a distinct identifier across all different user-facing

services and applications, including the OEM app, content provider apps and product

display. LSx sets a default unique name in the format “BrandName_XXXX” (XXXX denotes

last four digits of the MACID). OEM app/HOST MCU can provide an option to switch from

default name to a unique name for the end users, during the initial configuration or via the

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settings menu. Additionally, users can modify the name via the device webpage, Google

Home app, or as part of the WAC configuration process. This name persists across power

cycles however, it reverts to the default name following a factory reset.

The friendly name may consist of alphanumeric characters or special

symbols, with a maximum limit of 64 characters.

1. To read the Device name:

HOST MCU LSx

MB#90 GET Command

MB#90 SET Response

Acknowledgement

Response

No

Yes

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

90

NA

Variable

0

-

Response Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

90

SUCCESS/

FAILURE

Variable

Length of the

data field

<Data>

Data:

Data will be the device name in string format.

e.g., “Kitchen_Speaker”

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2. To update the Device name:

HOST MCU LSx

MB#90 SET Command

MB#90 ACK

Acknowledgement

Response

Yes

No

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

90

NA

Variable

Length of the

data field

<Data>

Data:

Data will be the new device name that is to be set in string format.

e.g., “Master_Speaker”

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format

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9.35. RxTx_MB# 91 (Network Info)

LS10/11

LS9

LS5B/6



APP

MCU



The HOST MCU/APP can utilize this message box to obtain either the IP address or the MAC

address of the device as per the specific requirement. Multiple options are available to

obtain the MACID or IP address for active interfaces or for specific interface, additional

information is provided in the data section.

HOST MCU LSx

MB#91 Command

SET

MB#91 SET Response

Acknowledgement

Response

No

Yes

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

91

NA

Variable

Length of the

data field

<Data>

Response Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

91

NA

Variable

Length of the

data field

<Data>

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Command/Response Data for LS10:

Command Data

Response Data

Description

MACADDR:wlan0

Wlan0:<mac address>

LSx provides wlan0 mac address.

e.g. Wlan0:AA:BB:CC:DD:EE:FF

MACADDR:eth0

Eth0:<mac address>

LSx provides eth0 mac address.

e.g. Eth0:AA:BB:CC:DD:EE:FF

MACADDR

Wlan0:<mac address>

Eth0:<mac address>

LSx will send two response packets:

Response 1: wlan0 mac address

Response 2: eth0 mac address.

MACADDR:

IPADDR

LSx provides IP address of the current active

interface. If none of the interface is active,

0.0.0.0 will be send. In network setup mode,

both p2p0 and p2p1 both will be active, in this

case p2p0 IP address will be send.

IPADDR:

IPADDR:wlan0

LSx provides IP address of wlan0 interface.

If wlan0 interface is not active, 0.0.0.0 will be

send.

IPADDR:eth0

LSx provides IP address of eth0 interface.

If eth0 interface is not active, 0.0.0.0 will be

send.

IPADDR:p2p0

LSx provides IP address of p2p0 interface.

If p2p0 interface is not active, 0.0.0.0 will be

send.

IPADDR:p2p1

LSx provides IP address of p2p1 interface.

If p2p1 interface is not active, 0.0.0.0 will be

send.

Command/Response Data for LS9:

Command Data

Response Data

Description

“” (Any data in the

3rd argument).

Wlan0:<mac address>

Eth0:<mac address>

• If the netif value is auto, it will send the

wlan0, eth0 mac address.

• If the netif value is eth0, it will send the

eth0 mac address else it will send the

wlan0 mac address.

MACADDR:

Wlan0:<mac address>

Device will send the wlan0 mac address.

IPADDR:

Interface-name

<IP address of the

interface>

Device will send IP address of the given

interface if the interface is UP.

IPADDR

If the eth0 interface is UP it will show the eth0

interface IP address else, it will show the

wlan0 interface IP address.

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Command/Response Data for LS5B/LS6:

Command Data

Response Data

Description

“” (Any data in the

3rd argument).

Wlan0:<mac address>

Eth0:<mac address>

If the ethernet interface is up, it will send the

eth0 mac address else if the netif value is

eth0, it will send the eth0 mac address or will

send the wlan0 mac address.

If an invalid interface is utilized to retrieve the MAC address, the display will

indicate "00:00:00:00:00:00" (Zero MAC).

Similarly, if an invalid interface is used to obtain the IP address, the display will

show "0.0.0.0" (Zero IP).

9.36. RxTx_MB# 92 (Device Details)

LS10/11

LS9

LS5B/6



×

APP

MCU



This MB is used by HOST MCU and OEM APPs to request for device details such as MAC

address, serial number, device firmware version, etc. LSx dynamically updates this data as

it receives the dependent data and shaping it into a JSON format.

Phase 1 - The below JSON will be formed when the device boots up completely:

Phase 2: The below JSON will be formed when HOST MCU sends or update HOST MCU

version:

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HOST MCU LSx

MB#92 GET Command

MB#92 SET Response

Acknowledgement

Response

No

Yes

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

92

NA

Length of

the data

-

Response Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

92

NA

Length of

the data

<Data>

Data:

JSON format provided below represents the optimal scenario; however, variations in the

format may occur depending on the data available at the time of request.

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{

macaddress: {

wlan0:, <wlanMACID>

eth0:, <ETH_MACID>

bt: <bt_MACID>

},

serialnumber: {

device_serialnumber:, <device_serial_number >

package_serialnumber:, :<package_serial_number>

},

versioninfo: {

castliteversion:,

devicefwversion:, :<device_fw_version>

mcuversion: :<mcu_version_number>

}

Where,

macaddress – It contains the interface MAC addresses of WLAN, BT and Ethernet.

serialnumber – It contains serial numbers of device.

versioninfo – It contains device firmware version in the below format:

e.g., eng.C4A.1001.026.036

Example,

{

macaddress: {

wlan0:00:50:43:02:FE:01,

eth0:02:35:B7:DC:98:6E,

bt:43:43:43:43:43:43

},

serialnumber: {

device_serialnumber:d5b785eaa3475df6169d,

package_serialnumber:<Package serial number received via MB #8>,

},

versioninfo: {

castliteversion:<Not updating now>,

devicefwversion:eng.C4A.3105.146.023,

mcuversion:146

}

The Castlite version is reserved for now.

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9.37. Rx_MB# 95 (Input Start)

LS10/11

LS9

LS5B/6



APP

MCU



This message box is used by the HOST MCU to switch the audio source to line input sources

like AUX, SPDIF, etc. These input audio sources will be directed to LSx from external

connectors/ADCs, LSx will read this audio input data, process it (optional) and play it out.

HOST MCU can trigger MB#95 with Appropriate params when user selects the desired

source using button control.

HOST MCU LSx

MB#95 SET Command

MB#50 SET Current Source (13)

MB#95 ACK

MB#10 SET New Source <source type>

MB#11 SET Allow

Acknowledgement

Response

Yes

No

Command Format for LS9 & LS6/5B:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

95

NA

Variable

0

NA

LS9 and LS6/5B doesn’t support SPDIF. It supports only AUX hence, there is

no data argument for LS9 and LS6/5B.

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Command Format for LS10:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

95

NA

Variable

Length of data

field

<Data>

Data:

Data

Description

AUX_START

To start the AUX playback.

SPDIF_START

To start the SPDIF playback.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

To go back to Feature Section click here.

9.38. Rx_MB# 96 (Input Stop)

LS10/11

LS9

LS5B/6



APP

MCU



This message box is used by the HOST MCU to stop the audio input sources described in

MB#95.

HOST MCU LSx

MB#96 SET Command

MB#96 ACK

Acknowledgement

Response

Yes

No

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Command Format for LS9 & LS6/5B:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

96

NA

Variable

0

NA

LS9 and LS6/5B doesn’t support SPDIF. It supports only AUX hence there is no data

argument for LS9 and LS6/5B.

Command Format for LS10:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

96

NA

Variable

Length

data field

<Data>

Data:

Data

Description

AUX_STOP

To stop the AUX playback.

SPDIF_STOP

To stop the SPDIF playback.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

To go back to Feature Section click here.

9.39. Rx_MB# 97 (External Playback)

LS10/11

LS9

LS5B/6



APP

MCU



This message box is used to notify LSx on “Start” or “Stop” of external playback. External

Playback is the playback from any sources like AUX, SPDIF, etc. that HOST MCU will directly

play using external DSP/CODEC without directing this audio to LSx. On receiving the

command “Start”, LSx internally manages the source selection as “external source” on

Source Switch module. HOST MCU can send this message box upon user selecting the

source selection button for external sources.

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HOST MCU LSx

MB#97 SET Command

MB#97 ACK

MB#50 SET Current Source 25

MB#10 SET New Source 25

MB#11 Allow

SET

Acknowledgement

Response

Yes

No

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

97

NA

Variable

Length of

Data

<Data>

Data:

Remote ID

Command Type

START

To start playback from external source.

STOP

To stop playback from external source.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

To go back to Feature Section click here.

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9.40. Rx_MB# 111 (TCP/IP Tunneling Start)

LS10/11

LS9

LS6/5B



-

APP

MCU

×



TCP Tunneling is a mechanism for HOST MCU to communicate with network devices or

mobile APPs by using the “TCP tunnel” offered by LSx. MCU developer predefines a port

number that LSx should use to communicate with Network TCP clients/APP. LSx will

accept connection request from this port and establishes a tunnel to pass to and forth the

TCP messages between network client/APP and the HOST MCU.

MB#111 is used by the HOST MCU to notify LSx on the port number which LSx should use

to communicate with APP/network clients.

HOST MCU LSx

MB#111 SET Command

ACKMB#111

Acknowledgement

Response

Yes

No

To start tunneling, HOST MCU must specify the port number using this message box. Once

triggered, LSx opens a TCP listening socket and is ready to accept connection from network

clients/APPs.

Command Format:

Remote

ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

111

0

Variable

Length of

Data

<Data>

Data:

Data is the port number. MCU developer will predefine the port number and send it to LSx.

Example of port number field: 4444.

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Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

To go back to Feature Section click here.

9.41. TxRx_MB# 112 (Tunnel Data)

LS10/11

LS9/X

LS6/5B



-

APP

MCU

×



Once a tunnel is created using the MB# 111, LSx opens a TCP listening socket and accepts

connection from network clients/APPs.

LSx can accept more than one TCP connections with a MAX limit set to 10.

All data received from TCP socket from any of the connections will be passed to the MCU

over this message box. MCU can also send data to connected clients using this message box.

This message box can be used in two scenarios:

1. MCU to send data to APP/network clients.

Here, MCU will send the data over MB# 112, LSx will tunnel this data to the APP/network

client.

HOST MCU LSx

MB#112 SET Command

MB#112 ACK

Acknowledgement

Response

Yes

No

2. LSx to send data to MCU.

Here, LSx will send the data received from the mobile APP/network clients to MCU over

MB# 112.

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HOST MCU LSx

MB#112 SET Command

Acknowledgement

Response

No

Below sequence diagram shows details of steps involved for using TCP tunneling.

MCU LSx Remote Device

MB# 111 (Tunneling Start) parameter

<port>

ACK

MB# 112 LUCI Header + data

Creates Socket and binds to port number and

stays in listening mode

App sends Data on TCP (No LUCI Headers) LSx

removes TCP/IP Header and adds LUCI header in

front of Data

Data encapsulated on TCP/IP packet

UART TCP

ACK

MB# 112 LUCI Header + data

Figure: TCP/IP Tunneling Sequence

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Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

112

0

Variable

Length of

Data

<Data>

Data:

Data is the TCP raw data.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

To go back to Feature Section click here.

9.42. Rx_MB# 114 (Reboot Request)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



During the OTA process, after the application completes the first stage of installation, the

LSx must reboot into bootloader mode to finish the remaining installation. In a system with

a HOST MCU, the LSx will request the HOST MCU to initiate this reboot. This reboot request

can be sent via MB#114. Upon receiving this command, the HOST MCU must send MB#115

to gracefully shut down the apps running on LSx.

This MB will be sent from LSx to HOST MCU whenever LSx requires a reboot for scenarios

such as firmware updates, factory reset, etc. HOST MCU must perform the following actions

upon receiving this command:

• Send MB#115 for graceful shutdown of LSx apps.

• Perform a hardware reset of LSx.

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HOST MCU LSx

MB#114 SET Command

MB#115 SET Response

Acknowledgement

Response

No

Yes, MB#115

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

114

0

Variable

Length of data

<Data>

Data:

Data is ‘reboot request’.

Response Format:

For response, refer MB#115.

To go back to Feature Section click here.

9.43. Tx_MB# 115 (Reboot Command)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



This MB is used by HOST MCU to send reboot command to LSx to do graceful shut down of

all LSx apps.

After reboot, HOST MCU waits for message box # 0xAAAA.

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HOST MCU LSx

MB#114 SET Command

MB#115 SET Response

Acknowledgement

Response

No

Response Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

115

0

Variable

0

-

To go back to Feature Section click here.

9.44. Tx_MB# 149 (Miscellaneous MCU Requests)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



LSx utilizes this MB to notify HOST MCU on various events and to take necessary actions.

Currently, it is employed for initiating a factory reset. In the future, this MB will undergo

enhancements to cater for any additional requirements.

1. Factory Reset Request

Upon receiving MB#149 with data facresetrequest, the MCU is prompted to

undertake preparatory steps for the factory reset. Subsequently, the MCU needs to

send MB#150 to LSx, signalling to proceed with the factory reset.

If a customer needs to include a factory reset option on the device webpage, upon

the user selecting this option, LSx will signal the MCU to execute a factory reset

utilizing this MB and it can be applied to fulfil any similar requirements.

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HOST MCU LSx

MB#149 SET Command

MB#150 SET Response

[facresetrequest]

Acknowledgement

Response

No

Yes, MB# 150

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

149

NA

Length of

the data

<Data>

Data:

Data

Description

facresetrequest

Requests MCU to perform factory reset. Upon receiving this

data, the MCU will prepare for factory reset and then signal

LSx via MB#150 to proceed further.

9.45. MB# 211 (Start Firmware Upgrade) - Deprecated

This MB is used only in LS6. On request for Firmware Upgrade from LSx over MB# 69,

HOST MCU either starts the firmware upgrade process or denies the firmware upgrade.

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9.46. Rx_MB# 213 (Music Service Credentials)

LS10/11

LS9

LS5B/6



-

APP

MCU



This MB is employed to share login credentials (Username & Password) of Music service to

LSx, enabling LSx to login to the corresponding music service using these provided

credentials.

This applies exclusively to specific music services that are browsed and played. For

instance, Airable supports services like TIDAL, Deezer, and Napster, which require user

login. When a user selects these music services first time, using HOST MCU/APP UI display,

a pop-up prompts them to enter their credentials and log into these respective services.

These login details are then provided to LSx through MB#213, and LSx utilizes them to

login to the designated music service.

This scenario doesn't apply when the APP directly implements the Airable UI by

communicating with Airable Cloud, bypassing LSx for browse control. In such cases, the

login is carried out directly by the APP with the music server.

Note that this is not applicable for native applications such as TIDAL Connect Native as the

login will be done using TIDAL app directly with TIDAL server.

HOST MCU LSx

MB#213 SET Command

Acknowledgement

Response

No

Command Format:

Remote

ID

Command

Type

Message Box

ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

213

0

Variable

Length of Data

<Data>

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Data:

The data format is as given below:

<Music Service>USERNAME_<username>, < Music Service >USERPASSWORD_<password>

< Music Service >: The name of music service such as TIDAL, QOBUZ, DEEZER, NAPSTER

and HIGHRESAUDIO

<Username>: End User login name

<Password>: End User login password.

E.g.,

DEEZERUSERNAME_libreteset@librewireless.com, DEEZERUSERPASSWORD_xyz@153

To go back to Feature Section click here.

9.47. Tx_MB# 223 (Firmware Download Progress)

LS10/11

LS9

LS5B/6



×

APP

MCU



This message box is used to send firmware download progress to the HOST MCU and app.

HOST MCU/APP LSx

MB#223 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

223

NA

Variable

Length of the

data field

<Data>

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Data:

Data

Description

UPDATE_STARTED

LSx detects a valid firmware update is available and about to start.

UPDATE_DOWNLOAD

Download of the firmware image is initiated.

UPDATE_IMAGE_AVAILABLE

LSx firmware image is downloaded successfully.

NO_UPDATE

This data is sent when the update is not available or fails to

download the firmware.

CRC_CHECK_ERROR

This error message will be sent if there are any failures in the

integrity (hash) or authenticity (sign verify) of the downloaded

image.

Additionally, for LS9 this data is sent when the downloaded image

CRC and the CRC written in the field <crc32check> of the XML file

used for internet upgrade do not match.

DOWNLOAD_FAIL

Firmware download is unsuccessful.

To go back to Feature Section click here.

9.48. Tx_MB# 230 (Audio Output FS)

LS10/11

LS9

LS5B/6



-

APP

MCU

×



This message-box is used by LSx to notify the sampling frequency (I2S-LRClock) to HOST

MCU, every time the sampling frequency changes. HOST MCU can adjust the DSP/DAC

settings (if any) on this sampling rate change notification. After sending the new sampling

rate, LSx waits for maximum of 1 sec for the response on MB#556. On receiving the

response (or on timeout) LSx assumes that HOST MCU has done the required changes and

LSx starts the playback.

Take into account that LSx provides two kinds of configurations: Fixed Frequency and

Variable Frequency. In the Fixed Frequency, the output sampling frequency is fixed as per

Additionally, the download percentage of firmware upgrade (0% -100%) will

also be sent on this message box for LS10.

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the value in the ENV ‘alsaoutputdevice’ (LSx performs a software sampling rate conversion

to convert the original song FS to this fixed FS). On the other hand, in the Variable

Frequency mode, the audio is played in its original frequency without any conversion, and

the ENV 'alsaoutputdevice' should be set as “default”. MB#230 is applicable only for

variable frequency mode.

Acknowledgement

Response

No

Yes, MB#556

HOST MCU LSx

MB#230 SET Command

MB#556 SET Response

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

230

Success /

Failure

Variable

Length of the

data

<Data>

Data:

Data will be sample rate of the current playback. The supported sample rates range from

8kHz -192kHz.

e.g., If the sampling frequency is 48kHz, data will be 48000. Similarly, if the sampling

frequency is 96kHz, data will be 96000.

Response Format:

For response, refer to Message Box 556.

To go back to Feature Section click here.

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9.49. Rx_MB# 232 (AC Powered)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



This message box is applicable only for battery powered devices. The purpose of this

message box is to safeguard the device from entering into undesirable situations like

running out of battery during firmware update.

LSx will update the firmware only if an AC adapter is connected (charging) or there is

sufficient battery power in the device. The MCU must update this message box in the

following conditions:

• On bootup

• Change in power state (Connecting or disconnecting AC adapter)

LSx will allow the firmware update to proceed only if this message box value is True.

HOST MCU LSx

MB#232 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

232

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

TRUE

The speaker is AC powered/above battery threshold and firmware

download/update can occur.

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FALSE

The speaker is NOT AC powered (running in battery) and in low battery

state, firmware download/update cannot occur.

To go back to Feature Section click here.

9.50. RxTx_MB# 235 (Trigger OTA)

LS10/11

LS9

LS5B/6



×

APP

MCU



LSx will automatically check for OTA updates on boot up and at regular intervals. This MB

allows manual triggering of OTA upgrades from HOST MCU or APP. Responding to MB#235

request, LSx queries the OTA server for available updates and proceeds with upgrade

process if a valid update is found.

HOST MCU LSx

MB#235 SET Command

MB#235 SET Response

MB#235 ACK

Acknowledgement

Response

Yes

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

235

NA

Length of data

<Data>

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Data:

Data

Description

TRIGGER_OTA

LSx will trigger an OTA update request, proceeds with the firmware

upgrade if a valid upgrade is found.

The progress of the firmware update can be monitored using MB#223.

Response Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

235

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

CHECKING_UPDATE

Checking for update. Refer MB#223 for update status.

UPDATE_INPROGRESS

If already some update is going on, MB#235 request will be ignored.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

To go back to Feature Section click here.

9.51. RxTx_MB# 238 (Forced Upgrade)

LS10/11

LS9

LS5B/6



-

APP

MCU

×



This MB facilitates forced OTA upgrades. LSx will automatically check for OTA updates on

boot up and at regular intervals. Additionally, MB#235 allows manual triggering of OTA

updates from HOST MCU or APP. Responding to MB#235 request, LSx queries the OTA

server for available updates and proceeds if found. However, customers have specified the

need to reapply a firmware update using the current firmware available on the OTA server,

even if it matches the version currently running on the device.

This requirement arises from the incorrect installation of the previous firmware upgrade

on the HOST MCU or DSP module, attributed to potential bugs or limitations in the HOST

MCU/DSP firmware update implementations. Introducing MB#238 aims to redo the

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firmware update and address the mentioned failures. The HOST MCU provides an option

for end users or service engineers to trigger MB#238 in such scenarios. Moreover, MB#238

can be employed for similar situations wherever applicable.

This is a special MB introduced to handle specific use cases. Contact Libre FAE and

confirm the use case and implications before handling this MB.

HOST MCU LSx

MB#238 SET Command

MB#238 SET Response

MB#238 ACK

Acknowledgement

Response

Yes

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

238

NA

Variable

Length of

Data

<Data>

Data:

Data

Description

REQ_FORCE_UPDATE

LSx will request OTA server for a forced firmware upgrade. OTA

server will validate the current firmware version of LSx and the

firmware version of the hosted image in the OTA server and proceed

with update only if the hosted image firmware version is greater than

or equal to the current firmware version running in the LSx. If the

hosted image firmware version is lower, the update will not be

triggered.

The progress of the firmware update can be monitored using

MB#223.

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Response Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

238

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

CHECKING_UPDATE

Checking for update. Refer MB#223 for update status.

UPDATE_INPROGRESS

If already some update is going on, MB#238 request will be ignored.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

To go back to Feature Section click here.

9.52. Rx_MB# 556 (Audio Output FS ACK)

LS10/11

LS9

LS5B/6



×

-

APP

MCU

×



This message box is sent from HOST MCU to LSx and serves as an acknowledgement for

MB#230. On receiving MB#230, HOST MCU can undertake essential adjustments, such as

configuring the DAC/DSP to accommodate the updated sampling frequency and then

acknowledge over MB#556 so that LSx can proceed with the playback.

HOST MCU LSx

MB#230 SET Command

MB#556 SET Response

Acknowledgement

Response

No

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Response Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

556

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

0

Success

1

Failure

0: HOST MCU can acknowledge the change by sending 0.

-1: In the event, the HOST MCU doesn’t acknowledges the sampling rate change, it can send

the value -1. However, this is never an expected scenario as HOST MCU decides to proceed

with the playback issuing MB#11 and configuring the system to accept variable FS and

HOST MCU cannot refuse it at this stage.

To go back to Feature Section click here.

9.53. RxTx_MB# 561 (Apple Home APP Inclusion Check)

LS10/11

LS9

LS5B/6



×

APP

MCU



Users can set up an AirPlay password using a mobile APP or webpage, but this is only

possible if the device isn't already configured to the Apple Home APP. If the device is

already part of the Apple Home APP, it takes precedence, and users can't change the

password. Therefore, it's important to verify whether the device is currently connected to

the Apple Home APP before attempting to modify the AirPlay password. MB#561 is used to

check if the LSx device is configured/added in the Apple Home APP.

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HOST MCU LSx

MB#561 SET Command

MB#561 SET Response

MB#561 Ack

Acknowledgement

Response

Yes

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

561

SET

Variable

Length of the

data field

<Data>

Data:

The data is “get”.

Response Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

561

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

0

Device is not configured in Apple home.

1

Device is configured in Apple home.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format

To go back to Feature Section click here.

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9.54. Rx_MB# 562 (AirPlay Password Request)

LS10/11

LS9

LS5B/6



×

APP

MCU



This MB is used to set/get the AirPlay password.

MCU LSHOST MCU LSx

MB#562 SET Command

MB#563 SET Response

MB#562 ACK

Acknowledgement

Response

Yes

No

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

562

SET

Variable

Length of the

data field

<Data>

Data:

The data will be sent in the below JSON format:

{

"action": "<control>",

"password": "<value>"

}

control: It can be ‘set’ or ‘get’

value: Applicable only for set, value should contain the password string to be set. For ‘get’,

it is not applicable, should be empty string (“”).

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e.g. {"action":"set","password":"111222"}

{"action":"get","password":""}

Response Format:

For response, refer to MB#563.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format

To go back to Feature Section click here.

9.55. Tx_MB# 563 (AirPlay Password Response)

LS10/11

LS9

LS5B/6



×

APP

MCU



This MB is the response to MB# 562.

MCU LSHOST MCU LSx

MB#562 SET Command

MB#563 SET Response

MB#562 ACK

Acknowledgement

Response

No

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Response Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

563

NA

Variable

Length of the

data field

< Data>

Data:

Response for "action": "set" triggered from MB# 562:

Data will be in the below JSON format:

{

"password": "<new password>",

"status": <value>

}

<new password> and <value> can be as given below:

Description

New password

Value

Example

The device password is

set successfully.

The password

entered in

MB#562.

0

{

"password": "111222",

"status": 0

}

Device is already

configured in Apple home.

Empty String

1

{

"password": "",

"status": 1

}

Invalid password.

(Empty, more than 32

characters)

The invalid

password

entered in MB#

562.

2

{

"password": "",

"status": 2

}

Invalid request from MCU

(Invalid JSON/wrong

data)

Empty String

3

{

"password": "",

"status": 3

}

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Response for "action": "get" triggered from MB# 562:

Data will be in the below JSON format:

{

"password": "<password>",

"status": <value>

}

<password> and <value> can be as given below:

Description

password

Value

Example

The AirPlay password is

retrieved successfully.

The existing

password

0

{

"password": "111222",

"status": 0

}

Device is already configured

in Apple home.

Empty String

1

{

"password": "",

"status": 1

}

To go back to Feature Section click here.

9.56. Rx_MB# 571 (Google Cast ToS and Usage Report -

Requests)

LS10/11

LS9/X

LS6/5B



×

APP

MCU



This MB is used by companion app/HOST MCU to:

• Update the user selection preference of ToS and Usage Report (Opt-In/Opt-Out). User

can accept/decline to these services and App/MCU to update the preferred status to

LSx.

• Get the current status of ToS and Usage reports preferences. This will be helpful to

update the UI as per the current selected preference.

The password can be set only if the device is not configured to home APP.

The password can be numbers, alphabets (upper and lower case), special

characters and the length will be 1 to 32.

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LSx will respond back in MB #572.

MB# 571 SET Command

APP LSX

MB# 572 SET Response

Acknowledgement

Response

No

Yes, MB# 572

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

571

NA

Variable

Length of

Message

<Data>

Data:

1. To update the User Selection preference

The data format will be:

{

“request_type”:“set”,

"id":"<ID>",

"action": "<ACTION>",

"user_ip": “<Client_IP>”,

"device_uuid": “<Unique_device_ID>”

}

Where,

ID: “tos” or “crash_report”

Use “tos” for ToS and “crash_report” for usage reporting Opt-in or Opt-out user

selections.

ACTION: “accepted” or “declined”

Update as per user selection. For ToS, LSx expects only accepted, if user declines,

app should take care of re-populating the ToS acceptance screen again as per the UX

guidelines from Google.

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In usage report, for opt-in send “accepted” and for opt-out send “declined.”

Client_IP: For network Apps (e.g., Mobile App), send the phone’s IP address, for HOST MCU

this can be empty.

Unique_device_ID: This functions as a distinct identifier for message filtering. The

app/HOST MCU can compare the unique ID in the response packet with the one sent,

determining if the response is intended for the sender. Since LSx broadcasts the response,

it's crucial for the app to verify that it corresponds to the request made by the app.

Every mobile app will possess a unique ID, which can be retrieved and inserted here. The

HOST MCU can produce a unique ID of 16/32 length or opt for any other suitable unique

IDs available.

Examples: Go to Example 1 & Example 2

2. Current Selected Preference

Use the below JSON to fetch the current value of ToS and Usage report from LSx:

{

“request_type”: ”get”,

"id": "status",

"device_uuid": <Unique_device_ID>

}

request_type: use “get”

id: use “status”, this will fetch the value for both ToS and usage reports.

Unique_device_ID: Unique ID for message filtration (refer above)

To go back to Feature Section click here.

The Terms of Service (ToS) should only be accepted once. The ToS state cannot

be changed until the device undergoes a Factory Data Reset (FDR).

* ToS should be accepted for stable channel/production firmware otherwise LSx will not

be advertised and be available to Cast on any content app. However, an exception is made

for beta/engineering firmware to proceed with Google Cast even if ToS is not accepted,

this exception is applicable only for development and debugging.

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9.57. Tx_MB# 572 (Google Cast ToS & Usage Report - Response)

LS10/11

LS9/X

LS6/5B



×

APP

MCU



LSx uses this MB to respond back to app/Host MCU for the requests that are made via

MB#571.

MB# 571 SET Command

APP LSX

MB# 572 SET Response

Response Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

572

NA

Variable

Length of

Message

<Data>

Data:

1. Response for “User selection Preference”

This is the response for the request To update the User Selection preference as mentioned

in MB#571. The format will be:

{

"id": "<ID>",

"status": "<STATUS>",

"status_msg": “<FAILURE_REASON>“,

“user_ip”: “<Client_IP>”,

"device_uuid": <Unique_device_ID>

“action": “<ACTION>”

}

ID: “tos” or “crash_report” as per the request command.

STATUS: “success” or “failure.” If the status is “failure” refer FAILURE_REASON in

status_msg for further details.

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FAILURE_REASON: The failure reason string can be used for debugging.

Client_IP: The same IP address of the client who requested data.

Unique_device_ID: The unique ID of the requested client.

ACTION: “accepted” or “declined,” it will be the same value as given in the action field of

request command format.

Example 1: for ToS

Command Format

Response Format

{

“request_type”: “set”,

"id": "tos",

"action": "accepted",

"user_ip": “192.168.1.30”,

"device_uuid": “2C76D223-4974-4F46-

B368-012E912B600E”

}

{

"id": "tos”,

"status": "success",

"status_msg": "”,

“user_ip”: “192.168.1.30”,

"device_uuid": “2C76D223-4974-4F46-

B368-012E912B600E”

“action": “accepted”

}

Example 2: for Usage Reports

Command Format

Response Format

{

“request_type”:“set”,

"id":"crash_report",

"action": "declined",

"user_ip": “192.168.1.30”,

"device_uuid": “2C76D223-4974-4F46-B368-

012E912B600E”

}

{

"id":"crash_report",

"status": "success",

"status_msg": "",

“user_ip”: “192.168.1.30”,

"device_uuid": “2C76D223-4974-4F46-

B368-012E912B600E”,

“action": “declined”

}

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2. Response for “Current selected Preference”

This is the response for the request Current Selected Preference as given in MB#571. The

format will be as follows:

{

"id": "status",

“tos”: “<ToS_STATUS>”,

“crash_report”: <USAGE_REPORT_STATUS>,

“status”: “success”,

"device_uuid": “<Unique_device_ID>”

}

ToS_STATUS: “activated” or “not_activated”

USAGE_REPORT_STATUS: It is a boolean value, it can be either true or false.

Unique_device_ID: The unique ID of the requested client.

Example:

Command Format

Response Format

{

“request_type”: ”get”,

"id": "status",

"device_uuid": ”2C76D223-4974-4F46-B368-

012E912B600E”

}

{

"id": "status",

“tos”: “activated”,

“crash_report”: true,

“status”: “success”,

"device_uuid": “2C76D223-4974-4F46-

B368-012E912B600E”

}

To go back to Feature Section click here.

9.58. RxTx_MB# 573 (TimeZone Configuration)

LS10/11

LS9

LS5B/6



×

APP

MCU



×

This MB allows users to adjust the TimeZone to suit their preferences or retrieve

information on the currently selected TimeZone. Libre operates an NTP Server, which

relies on TimeZone settings to accurately update the current time according to the selected

Zone. TimeZone data holds significance for LSx, as it is utilized internally for various

actions, such as scheduling OTA updates at specific times (e.g., 2:00 AM daily). The Host

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LIBRE CONFIDENTIAL

MCU can retrieve the TimeZone format and display the time on the display, refer to

MB#229 for more details.

If the TimeZone is not explicitly set, LSx defaults to UTC. LSx maintains the set TimeZone

persistently in the NV item, TimeZone.

App can fetch the current time zone from mobile services and set it silently as a part of set

up flow or even provide UI for user interaction to set it. In addition, in settings an option

can be provided for users to change the TimeZone.

Reading the Current Time Zone

App can GET the current time zone from LSx using MB#573 at any point of time.

MB# 573 GET Command

APP LSX

MB# 573 SET Response

Acknowledgement

Response

No

Yes

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

GET

573

NA

Variable

0

-

Response Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

573

NA

Variable

Length of

Message

<Data>

Data:

The data format is a string (“continent/city”) with TimeZone in IANA format.

E.g.: “Asia/Kolkata”

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Configuring the Current Time Zone

MB# 573 SET Command

APP LSX

MB# 573 Ack

Acknowledgement

Response

Yes

No

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

573

NA

Variable

Length of

Message

<Data>

Data:

The data format is as given below:

{

“timezone_oem”: “<TimeZone>”,

"time_in_12_hour_format": <12_HOUR_FORMAT>

}

TimeZone: Configured TimeZone in IANA format (continent/city).

12_HOUR_FORMAT: true or false in Boolean format. LSx is not handling this currently, it is

reserved for future use.

Eg:

{

“timezone_oem”: “Asia/Kolkata”,

"time_in_12_hour_format": false

}

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format

To go back to Feature Section click here.

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9.59. Rx_MB# 611 (MCU-LSx Standby)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



The HOST MCU communicates to LSx on standby state through this MB, exchanging both

commands and acknowledgements. There are four scenarios involved.

1. When the device enters standby:

The HOST MCU can initiate the system's standby mode either through user input by

pressing the standby button or automatically in the event of an inactivity timeout.

When the standby entry command is received, LSx performs internal housekeeping

tasks, makes adjustments to playback states as needed, and then sends an

acknowledgment back to the HOST MCU.

Acknowledgement for standby from LS10

Enter standby from MCU

MB# 611 SET Command

(Data: MCU_ENTERED_STANDBY)

MB# 612 SET Command

(Data: ACK_MCU_ENTERED_STANDBY)

HOST MCU LSx

User button press/

Inactivity timeout

(Enter Standby mode)

2. Standby exit from HOST MCU:

Exiting standby mode can be triggered by pressing buttons or through relevant actions

on the HOST MCU, including button presses or interactions with the display. When the

standby exit command is received, LSx performs internal housekeeping tasks, makes

adjustments to playback states as needed, and then sends an acknowledgment back to

the HOST MCU.

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User button press

(Exit standby)

Acknowledgement

Exit standby from MCU

MB# 611 SET Command

(Data: MCU_EXITED_STANDBY)

MB# 612 SET Command

(Data: ACK_MCU_EXITED_STANDBY)

LSx

HOST MCU

3. Standby exit on LSx events:

LSx can command HOST MCU to exit from standby when specific events originate from

LSx. e.g., playback trigger, bluetooth connection, etc. Upon receiving a playback start

signal from any source, LSx will verify the device's standby status using its internal

state variables. If the device is in standby, LSx notifies the HOST MCU to exit standby.

LSx then awaits the HOST MCU's response to confirm its exit from standby before

proceeding with MB#10 to initiate playback. It is crucial for the HOST MCU to promptly

exit standby and respond to LSx to minimize playback latencies. It should be noted that

many music services have stringent certification requirements, necessitating the

commencement of playback within a few seconds.

Exit standby from MCU

MB# 611 SET Command

Data: MCU_EXITED_STANDBY

MB# 612 SET Command

Data: MCU_EXIT_STANDBY

Acknowledgement

MB# 612 SET Command

(Data: ACK_MCU_EXITED_STANDBY) Playback starts

MCU exit from

standby

HOST MCU LSx

User Interaction

E.g. Playback trigger

4. Standby entry & exit from content provider APPs:

There are options to enable or disable device standby from content applications like

ROON. In such instances, LSx utilizes this message box to enter or exit standby.

4a. Standby entry from content provider APPs:

When the user presses the standby entry icon in content provider APPs.

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Acknowledgement for standby from LS10

Enter standby from MCU

MB# 611 SET Command

(Data: MCU_ENTERED_STANDBY)

MB# 612 SET Command

(Data: ACK_MCU_ENTERED_STANDBY)

HOST MCU LSx

User taps standby entry

option in content

provider APPs

Command to MCU to force enter into standby

MB# 612 SET Command

(Data: MCU_ENTER_STANDBY)

4b. Standby exit from content provider APPs:

When the user presses the standby exit icon in content provider APPs.

Exit standby from MCU

MB# 611 SET Command

Data: MCU_EXITED_STANDBY

MB# 612 SET Command

Data: MCU_EXIT_STANDBY

Acknowledgement

MB# 612 SET Command

(Data: ACK_MCU_EXITED_STANDBY)

MCU exit from

standby

HOST MCU LSx

User taps standby exit

option in content

provider APPs

Acknowledgement

Response

No

Yes, MB#612

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

611

NA

Length of data

<Data>

Data:

Data

Description

MCU_ENTERED_STANDBY

To notify LSx when the HOST MCU enters standby mode.

MCU_EXITED_STANDBY

To notify LSx when the HOST MCU existed standby mode.

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Response Format:

For response, refer to MB# 612.

9.60. Tx_MB# 612 (LSx-MCU Standby)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



LSx communicates to HOST MCU on standby state through this MB, exchanging both

commands and acknowledgements. There are four scenarios involved. The scenarios are as

explained in MB# 611.

Acknowledgement

Response

No

Yes, MB# 611

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

612

NA

Variable

Length of

Data

<Data>

Data:

Data

Description

ACK_MCU_ENTERED_STANDBY

Acknowledgement to MB#611 that the HOST MCU has

entered Standby state.

ACK_MCU_EXITED_STANDBY

Acknowledgement to MB#611 that the HOST MCU has exited

Standby state.

MCU_ENTER_STANDBY

LSx sends this command data to HOST MCU to enter standby.

MCU_EXIT_STANDBY

LSx sends this command data to HOST MCU to exit standby.

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9.61. RxTx_MB# 621 (HOST Settings)

LS10/11

LS9

LS5B/6



×

APP

MCU



Certain customers will have custom features that are mostly managed by HOST MCU and

customers can design their Web UI or APP with options to enable or disable this feature.

This MB is used to update the status of such features to HOST MCU when user changes

these settings from Web UI/APP. HOST MCU records and saves these settings and

subsequently initiate corresponding actions.

In addition, these features and states are managed by HOST MCU, LSx will not save the

status in its persistent region (NV), HOST MCU should save the status and on every bootup,

HOST MCU should update the current status to LSx so that LSx can populate the value for

these features in the respective UI.

The features supported by this MB will be mostly customer specific and might require

custom implementations to accommodate new requirements. Discuss with Libre FAE to

explore the utilisation of existing features or the addition of new ones.

An example of one such feature is ‘Start Volume Limit’ and ‘Power Sleep Timer.’.

Startup Volume Limit:

This feature is implemented to ensure that when the device powers up, it doesn't start

playback at the prior volume level. Instead, it commences at a lower volume and gradually

raises it until it matches the volume level prior to the reboot.

For instance, if the device's volume was initially set to 90 and the device is rebooted and if

the startup volume limit feature is enabled, playback starts at a lower volume, such as 30,

and then gradually escalates to reach the desired 90 as per customer requirement.

User is provided with an option to turn ON/OFF feature via webpage or application. When

user selects his desired preference through UI, LSx communicates this status to HOST MCU

using MB#622 via "st_volume_limit" field in JSON. The HOST MCU is responsible for

preserving this setting.

Following bootup, during the initial playback, the HOST MCU reviews the stored startup

volume limit flag. If it's enabled, the HOST MCU takes charge of the volume gain settings of

the DAC/DSP to achieve the volume ramp-up in accordance with the customer's

requirements.

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After every boot-up, it is the responsibility of the HOST MCU to keep LSx informed about

the current status of the startup volume limit.

Power Sleep Timer:

If the product does not achieve a successful standby state consuming less than 0.5watts

while maintaining wireless network connection (which is required to meet current ErP

requirements), Power Sleep Timer is used by the customer to control the power state of the

product. The Power Sleep Timer offers flexibility to users, enabling them to choose

between two options: either maintaining a Wi-Fi connection, which consumes additional

power, or allowing the device to enter true standby mode, consuming less power but losing

network connectivity.

HOST-MCU LSx Web UI

**Note: After boot up, if HOST MCU does not send MB#621 to LSx, display the default status as 'false' for st_volume_limit/power_sleep_timer and

firmware details as empty.

Boot Up

MB#621

User updates the st_volume_limit/

power_sleep_timer from Web page

Updates HOST MCU over

MB#622

App

Updates details on webpage

Updates details on App

User updates

st_volume_limit/

power_sleep_timer from

mobile APP

Updates HOST MCU over

MB#622

App notifies LSx with updated details

MB#621

Acknowledgement

Response

No

Yes, MB#622

Command Format:

Remote ID

Command

Type

Message

Box ID

Comman

d Status

CRC

Data Length

Data

0xAAAA

SET

621

NA

Length of data

<Data>

Data:

Data will be in JSON format including the values for various features.

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Data for Startup Volume Limit & Power Sleep Timer:

{

"hostmcusettings":{

"power_sleep_timer":<Boolean>,

"st_volume_limit":<Boolean>

},

"firmware_info":{

"product_mcu":"<String>",

"bt_version":"<String>"

}

If the value is true for power_sleep_timer, the option will be enabled.

If the value is true for st_volume_limit, startup volume limit will be enabled and HOST MCU

to ramp up the volume gradually.

“firmware_info” is specific to certain customers and it gives firmware

information like product MCU version.

e.g.

{

"hostmcusettings":{

"power_sleep_timer":true,

"st_volume_limit":true

},

"firmware_info":{

"product_mcu":"123",

"bt_version":"123"

}

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9.62. Tx_MB# 622 (HOST Settings Status)

During the boot-up process, HOST MCU must transmit a JSON message (MB#621) that

includes the status of the startup_volume_limit and power_sleep_timer, as well as

information about the PMCU and BT_Version. Upon receiving MB#621, LSx responds to the

HOST MCU with MB#622, containing a corresponding JSON message.

When accessing the webpage, LSx will update the current status of the

startup_volume_limit, power_sleep_timer, PMCU version and BT version, based on the

messages received from the HOST MCU. If the app needs to display these details, it can

retrieve all the relevant information in JSON format by reading MB#622.

Whenever there is a change in the status of the startup_volume_limit or power_sleep_timer

from the webpage, LSx notifies the HOST MCU via MB#622 containing all the details with

the updated JSON message.

If a user changes the status of the startup_volume_limit or power_sleep_timer using the

app, the app should notify LSx through MB#621 by sending a JSON object with the modified

values. Subsequently, LSx will update MB#622 with all the details and send it to HOST MCU.

HOST-MCU LSx Web UI

**Note: After boot up, if HOST MCU does not send MB#621 to LSx, display the default status as 'false' for st_volume_limit/power_sleep_timer and

firmware details as empty.

Boot Up

MB#621

User updates the st_volume_limit/

power_sleep_timer from Web page

Updates HOST MCU over

MB#622

App

Updates details on webpage

Updates details on App

User updates

st_volume_limit/

power_sleep_timer from

mobile APP

Updates HOST MCU over

MB#622

App notifies LSx with updated details

MB#621

Acknowledgement

Response

No

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Command Format:

Remote ID

Command

Type

Message

Box ID

Comman

d Status

CRC

Data Length

Data

0xAAAA

SET

621

NA

Length of data

<Data>

Data:

Data will be in JSON format including the values for various features.

Data for Startup Volume Limit & Power Sleep Timer:

{

"firmware_info":{

"product_mcu":"<String>",

"bt_version":"<String>"

},

"hostmcusettings":{

"power_sleep_timer":<Boolean>,

"st_volume_limit":<Boolean>

}

e.g.

{

"firmware_info":{

"product_mcu":"123",

"bt_version":"123"

},

"hostmcusettings":{

"power_sleep_timer":true,

"st_volume_limit":true

}

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9.63. RxTx_MB# 651 (Log Report)

LS10/11

LS9

LS5B/6



×

APP

MCU



When user reports an issue from app, this MB is used by companion app/HOST MCU to

send the data in JSON format to LSx. The data consists of App info, User info and details

about the issue.

Device will process this data and upload it to the server along with device logs.

LSx will respond to app/HOST MCU through the same MB.

MB# 651

HOST MCU/APP LSX

CommandSET

MB# 651 ResponseSET

Acknowledgement

Response

No

Yes

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

651

NA

Variable

Length of the

data field

<Data>

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Data:

The data format:

{

"app_info" :

{

"app_version" : “<app version>”,

"brand" : “<brand>”,

"date_time" : “<date and time>”,

"model" : “<model>”

},

"description" : “<log report>”,

"email" : “email”,

"name" : “name”,

"source" : “<app>” ,

"time" : “<time>”

"uuid" : “<unique ID>”

}

Where,

“app_version” - current version of the mobile application

“brand” - mobile phone brand

“date_time” - date and time when the issue was reported. The standard format is 2024-04-19

17:41:56 +05:30

“model” - mobile phone model number

“description” - details on the issue

“name” - reporter’s name (optional)

“email” - reporter’s mail id (optional)

“source” - source from which the issue is triggered (in this case, source is app)

“uuid” - unique identifier of the log report (uuid type 1). App generates new uuid for each

and every log report.

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For example,

{

"app_info" :

{

"app_version" : "1.6(1.0)",

"brand" : "samsung",

"date_time" : "2024-04-22 13:05:04.161 IST",

"model" : "SM-M536B"

},

"description" : "dut 3 long hour ",

"email" : "",

"name" : "",

"source" : "App",

"time" : "6 Hours",

"uuid" : "a5757f08-b0c8-4377-8b29-0a0baa79b151"

}

Response Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

651

NA

Variable

1

<Data>

Data:

0 - File uploaded successfully.

1 - File upload unsuccessful.

9.64. Rx_MB# 653 (MCU Log Data)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



This message box is used by the HOST MCU to transfer MCU logs to the LSx. The MCU can

send logs with a size of up to 2KB per transfer. The LSx responds to the MCU via MB# 654.

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HOST MCU LSX

MB# 653 SET Command

MB# 654 SET Response

MB# 653 ACK

Acknowledgement

Response

Yes

Yes, MB#654

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

653

NA

Variable

Length of the

data field

<Data>

Data:

The log dump received in this MB will have the MCU logs in compressed/uncompressed

format with a custom log header of 12 bytes.

The header format of MCU log is defined below:

Bytes

Description

0 to 3

Magic ID

4

MCU Number

5

Compression Format

6,7

Sequence Number

8,9

CRC (optional)

10,11

Reserved

< Log size >

Log Dump

Magic ID: This is a unique ID used for identification of the data being received/

transmitted.

Magic ID Format: ML<CRC enable/disable><protocol version>

Our existing protocol version is set as 0. The accepted values for magic ID’s are as follows:

- ML00 - CRC Disabled

- ML10 - CRC Enabled

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MCU Number: In case of multiple MCUs within a product, it's important to identify the

MCU ID with the received logs. MCU Number helps differentiate between logs generated by

different MCUs. LSx supports maximum 3 MCUs.

Values: 1 / 2 / 3

Compression Format: This indicates the compression format of the shared logs.

LSx will support the following values for compression format:

- 0 - No Compression

- 1 – Heatshrink

- 2 - gzip

Sequence Number: The MCU needs to send an incremental sequence number for each

transferred log.

CRC: This is an optional field to check the integrity of the received logs. If CRC is enabled in

the magic ID, the MCU must calculate the CRC value of the log data and include it here.

Log Dump: Log received from the Host MCU and the size must not exceed 2KB.

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9.65. Tx_MB# 654 (MCU Log Response)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



This message box is used by LSx to send the response to Host MCU.

Upon receiving the logs from Host MCU via MB# 653, LSx uses this message box to notify

the status of log reception to Host MCU.

HOST MCU LSX

MB# 653 SET Command

MB# 654 SET Response

MB# 653 ACK

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

654

NA

Variable

Length of the

data field

<Data>

Data:

Data should be in the below JSON format:

{

"response":{

"status":<log_status>,

"seqNo":<sequence number>

}

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Log_status: Status of the log received in MB# 653. The possible values are success and

failure.

Sequence number: Sequence number of the log header received in MB# 653.

e.g.,

{

"response":{

"status":"success",

"seqNo":12345

}

9.66. Tx_MB# 655 (MCU Log Request)

LS10/11

LS9

LS5B/6



×

App

MCU

×



This message box is used by LSx to request MCU logs in scenarios such as system reboot,

system crash, log reporting, etc. Upon receiving the request from LSx, Host MCU transmits

the logs to LSx through MB# 653.

HOST MCU LSX

MB# 655 SET Command

MB# 653 SET Response

Acknowledgement

Response

No

Yes, MB# 653

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Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

655

NA

Variable

Length of the

data field

<Data>

Data:

Data should be in the below JSON format:

{

"request":{

"action":"log_request"

}

9.67. Tx_MB# 661 (BLE Wi-Fi Config-Event Monitor)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



During the Wi-Fi setup process, LSx utilizes the BLE protocol to establish a connection with

the Companion APP. This procedure involves multiple steps, including LSx advertising its

BLE device, the user selecting the device via the Companion APP, establishing a connection

between the mobile application and LSx using BLE, transmitting user-entered Wi-Fi

credentials over this connection to LSx, LSx connecting to the selected Access Point, and

updating the outcome of the entire network setup for the end user.

HOST MCU LSx

MB#661 SET Command

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This MB fulfills the role of updating the status of each step in this workflow to the Host

MCU. These detailed event updates provide the Host MCU with the granularity required to

undertake necessary actions or implement precise updates to the display interface.

Acknowledgement

Response

No

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

661

NA

Length of

the data

<Data>

Data:

Data

Description

1

LSx started BLE Advertisement

2

Stop Advertisement

5

Waiting for client Connection

6

Client connected

7

Client disconnected

8

Waiting for client event

9

Got play tone request

10

Playing tone

12

Reply friendly name request

14

Reply security details request

16

Reply scan List request

21

Got credentials from APP

24

Connecting to Wi-Fi

25

Connection success

26

Connection timeout

27

Wrong password

28

Connection fail

35

BLE in Setup mode after FDR

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9.68. Rx_MB# 663 (BLE Remote Event Request)

LS10/11

LS9

LS5B/6



×

APP

MCU



This message box allows you to check BLE remote feature availability, monitor connection

status and manage pairing and unpairing controls.

HOST MCU LSx

MB#663 SET Command

MB#664 SET Response

MB#663 ACK

Acknowledgement

Response

Yes

Yes, MB#664

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

663

NA

Variable

Length of the

data field

<Data>

Data:

Data will be in JSON format as shown below:

{

"action": "check /pair/unpair/remote status",

}

Data

Description

0

Success/Paired/Connected

1

Failure/Unpaired/Disconnected

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Response Command:

For response, refer to Message Box 664.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

9.69. Tx_MB# 664 (BLE Remote Event Response)

LS10/11

LS9

LS5B/6



×

APP

MCU



This message box is used by LSx as a response to MB#663.

HOST MCU LSx

MB#663 SET Command

MB#664 SET Response

Acknowledgement

Response

No

Response Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

664

NA

Variable

Length of the

data field

<Data>

Data:

Data will be in JSON format as shown below:

{

"action": " check /pair/unpair/remote status",

"status": 0/1/ {" paring ": 0/1, "connection":0/1}

}

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Data

Description

0

Success/Paired/Connected

1

Failure/Unpaired/Disconnected

9.70. Tx_MB# 691 (Cellular Mode)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



After the system boots up, HOST MCU should inform LSx via MB#692 if the 'Cellular Mode'

is set to 'ON' or 'OFF'.

HOST MCU LSx

MB#691

MB#692

SET Command

Response

SET

Acknowledgement

Response

No

Yes, MB#692

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

691

NA

Length of

the data

<Data>

Data:

Data will be in JSON format including the values for various features.

Data for Cellular Mode:

{ "cellularmode": 1}

Values: 0 or 1

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If the value is 1, cellular mode is ON.

If the value is 0, cellular mode is OFF.

9.71. Tx_MB# 692 (Cellular Modem Status)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



When the connection is established between LSx and cellular modem, the device is in

cellular mode (Wi-Fi unavailable), LSx will send the status to the HOST MCU.

HOST MCU LSx

MB#691

MB#692

SET Command

Response

SET

Acknowledgement

Response

No

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

692

NA

Length of

the data

<Data>

Data:

Data will be in JSON format including the values for various features.

Data for Cellular Modem Status:

{ " cellularmodemstatus": 1}

Values: 1

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If the value is 1, cellular modem connection is successful.

9.72. Tx_MB# 701 (OTA LSx Actions)

LS10/11

LS9

LS5B/6



×

APP

MCU

×



This message box is used by LSx to update its firmware via OTA. The LSx sends MB#701 to

request permission from the HOST MCU for the firmware update. The HOST MCU responds

with MB#702, either granting permission for the update or instructing to skip it. The LSx

then acknowledges this in MB#701, indicating whether the firmware update has been

skipped or initiated.

HOST MCU LSx

MB#701 SET Command

MB#702 SET Response

MB#701 SET Status Response

Acknowledgement

Response

No

Yes, MB#702

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

701

NA

Variable

Length of the

data field

<Data>

Command Data:

Data will be in JSON format as shown below:

{

"type": "request",

"request": "allowupdate"

}

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Data

Description

allowupdate

Requesting to initiate an update

Status Response Data:

Data will be in JSON format as shown below:

{

"type": "status",

"status": "updateskipped"

}

{

"type": "status",

"status": "updatestarted"

}

Data

Description

updateskipped

Skipped the firmware update

updatestarted

Started the firmware update

Response Command:

For response, refer to Message Box 702.

9.73. Rx_MB# 702 (OTA User Actions)

LS10/11

LS9

LS5B/6



×

App

MCU

×



This message box is used by HOST MCU as a response to MB#701 granting permission for

the LSx firmware update via OTA or instructing to skip it.

HOST MCU LSx

MB#701 SET Command

MB#702 SET Response

MB#701 SET Status Response

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Acknowledgement

Response

No

Yes, MB#701

Response Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

702

NA

Variable

Length of the

data field

<Data>

Data:

Data will be in JSON format as shown below:

{

"type": "response",

"request": "allowupdate",

"response": "proceed"

}

{

"type": "response",

"request": "allowupdate",

"response": "skip"

}

Data

Description

proceed

To proceed with the firmware update

skip

To skip the firmware update

9.74. Tx_MB# 43690 (LSx LUCI Ready)

LS10/11

LS9

LS5B/6



APP

MCU

×



Once LSx platform boots up and initializes all the essential modules and when it is ready for

LUCI communication, it notifies HOST MCU through MB#43690.

After powering on/resetting the system, LSx will trigger this MB after completing its

bootup sequence. The timing of this MB transmission may differ across platforms as per

respective bootup sequence, (Approximately 15-40 secs). It is fairly assumed that HOST

MCU will be booting much faster, initialise its LUCI stack and is waiting for this MB to

proceed with LUCI communication.

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The data sent over this Message-Box from LSx to HOST MCU will be a fixed data

‘0xAAAAAAAAAA’ (10 times hex A). HOST MCU can start the communication as soon as it

reads 0xAAAAAAAAAA data in the data payload.

MB#9 SET Response

HOST MCU LSx

MB#43690 SET Command

Acknowledgement

Response

No

Yes, MB#9

Command Format:

Remote

ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

43690

NA

Variable

Length of

Data Field

<Data>

Data:

The data will be fixed as 

Response Format:

For response, refer to Message Box 9.

To go back to Feature Section click here.

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10. Message Boxes - Format Upgrade Ahead

The message boxes outlined below are yet to be worked upon by the Libre LUCI core team.

Consequently, there may be minor errors and potential confusion associated with these

message boxes. Despite this, in order to promptly release the document in the new

template, we have incorporated these message boxes here. They are scheduled for a

comprehensive review and content addition. These message boxes are currently not linked

to the feature section, but subsequently will be integrated into the main section (LUCI

Message Boxes) during the upcoming document releases.

10.1. RxTx_MB# 7 (Google Cast Version Information)

LS10/11

LS9

LS5B/6



×

APP

MCU



This message box can be used to query the Google Cast Version Information of LSx speaker.

Based on MCU request, LSx sends Google Cast Version Information to MCU.

HOST MCU LSx

MB#7 GET Command

MB#7 SET Response

Acknowledgement

Response

No

Yes

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

7

NA

Variable

0

-

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Response Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

7

NA

Variable

Length of data

<Data>

Data:

Data is Google cast version information.

10.2. Tx_ MB#36 (USB Device Disconnected)

LS10/11

LS9

LS5B/6



APP

MCU



This MB is used by LSx to inform HOST MCU if in case USB is disconnected on runtime.

This MB is applicable only for a valid UART interface where HOST MCU communication is

possible.

HOST MCU LSx

MB#36 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

36

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

1

Disconnected

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10.3. Rx_MB# 37 (Graceful Shutdown)

LS10/11

LS9

LS5B/6



App

MCU

×



This message box is used by the HOST MCU to gracefully shutdown LSx module.

After receiving the command, LSx module will de-register itself from Bonjour,

disconnecting active music services (AirPlay, Spotify, Cast, etc.), SSDP and

LUCI LSSDP protocols. LSx completes critical tasks like saving file, ENV items, etc. and

responds back in the same message box the final status. HOST MCU has to discontinue the

supply (3v3 supply in case of LS6) to LSx after receiving this command.

HOST MCU LSx

MB#37 SET Command

MB#37 ACK

Acknowledgement

Response

Yes

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

37

NA

Variable

0

<Data>

Data:

Data

Description

1

Graceful Shut down

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

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10.4. Tx_ MB# 38 (USB Device Connected)

LS10/11

LS9

LS5B/6



App

MCU

-



This MB is used by LSx to inform HOST MCU if in case any USB device is connected on

runtime. This MB is applicable only for a valid UART where HOST MCU communication is

possible.

HOST MCU LSx

MB# 38 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

38

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

0

Disconnected USB

1

Connected USB

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10.6. Rx_MB# 72 (Trigger Wi-Fi Scan)

LS10/11

LS9

LS5B/6



×

App

MCU



This message box serves the purpose of initiating a Wi-Fi scan within LSx when the user

selects "Scan SSID List" in the APP/Web UI. The HOST MCU transmits MB#72 to LSx,

prompting LSx to search for accessible APs and compile the SSID List. The scan results will

be conveyed through MB# 73.

HOST MCU/APP LSx

MB#72 SET Command

MB#73 SET Response

MB#72 ACK

Acknowledgement

Response

Yes

Yes, MB#73

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

72

NA

Variable

Length of Data

field

<Data>

Data:

Response Format:

For response, refer to MB# 73.

Acknowledgement:

Data

Description

1

Trigger Wi-Fi scan

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An acknowledgment will be sent following the format outlined in ACK Format.

10.7. Tx_ MB# 73 (Get Wi-Fi Scan Results)

LS10/11

LS9

LS5B/6



×

App

MCU



This message box is used to send the Wi-Fi scan results in JSON format from LSx to HOST

MCU as a response to MB# 72.

HOST MCU/APP LSx

MB#72 SET Command

MB#73 SET Response

MB#72 ACK

Acknowledgement

Response

No

Response Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

73

NA

Variable

Length of the

data field

<Data>

Data in JSON Format:

{

"Items": [{

"SSID": "<SSID Value>",

"Security": "<Security Value>"

}, {

"SSID": "<SSID Value>",

"Security": "<Security Value>"

}]

}

SSID Value: Name of Wi-Fi Network

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Security Value: Type of security protocol

Example:

"Items": [{

"SSID": "vodafone4058ED",

"Security": "WPA-PSK"

}, {

"SSID": "Libre",

"Security": "WPA-PSK"

}]

}

10.8. RxTx_MB# 123 (Interface IP Address Info)

LS10/11

LS9

LS5B/6

×



×

App

MCU

×



This Message box is used to get LSx device current Network Information such as IP address,

WI-FI, interface, etc.

HOST MCU LSx

MB#123 Command

MB#123 SET

GET

Response

Acknowledgement

Response

No

Yes

Command Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

123

NA

Variable

Length of the

data field

<Data>

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Response Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

123

NA

Variable

Length of the

data field

<Data>

Data:

Eth:IP address or Wlan: IP address

e.g., Eth:192.168.1.100

Wlan:192.168.1.101

10.9. RxTx_ MB# 124 (Network Status)

LS10/11

LS9

LS5B/6



×

App

MCU



×

LSx informs the HOST MCU about the current network status of various interfaces like

WLAN, ETH, P2P and various configuration modes such as WAC/SAC/LSx-Connect.

When there is a change in Network Type or Network Status this message is sent to the

HOST MCU. The HOST MCU can always send a GET in the same MB to know about the

current status of connectivity.

HOST MCU LSx

MB#124 Command

MB#124

GET

SET Response

Acknowledgement

Response

No

Yes

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Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

124

NA

Variable

Length of the

data field

-

Response Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

124

NA

Variable

Length of the

data field

Network

Status

Data:

The Data length field is always 17 Bytes. Data has the following format:

<active_Network>#WLAN,status#ETH,status#P2P,status#CONF,status

Where,

• active_Network is the current active network interface, values for the Network Type

/ Network Interface are as below:

o 1 = WLAN

o 2 = ETH

o 3 = P2P

o 4 = WAC/SAC/LS-Connect

• WLAN, Status is as below:

o 0 = WLAN is not active

o 1 = WLAN is active

• ETH, Status is as below:

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o 0 = Ethernet is not active

o 1 = Ethernet is active

• P2P, Status is as below:

o 0 = P2P is not active

o 1 = P2P is active

• CONF, Status is as below:

o 0 = WAC / SAC / LS-Connect configuration mode is not active.

o 1 = WAC / SAC / LS-Connect configuration mode is active.

For Example,

If the current active network type/network interface is WLAN, and LSx is connected to the

Network over WLAN then, LSx sets the data field of Message box#124 to:

• In Home-Network Mode or Infrastructure Mode, values will be

1#1,1#2,0#3,0#4,0

• In MRA HN mode or Miracast, values will be

1#1,1#2,0#3,0#4,0

• In MRA SA mode, values will be

3#1,0#2,0#3,1#4,0

• In Configuration mode (WAC/SAC/LSx-Connect) values will be

4#1,0#2,0#3,0#4,1

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10.10. RxTx_ MB# 125 (Network Conf)

LS10/11

LS9

LS5B/6



×

App

MCU



×

This message box can be used by HOST MCU or Libre App controller to make LSx module

connect to specific Access points.

Both App developers and HOST MCU can make use of this message box to receive the

credentials of Home/commercial Access Point from the user and send the same to LSx

module.

LSx module will connect to this AP once it receives the credentials.

HOST MCU/APP LSx

MB#125 SET Command

MB#124 SET Response

Acknowledgement

Response

No

Yes, 124

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

125

NA

Variable

Length of the

data field

<Data>

Data:

e.g. LibreAP,Libre@123

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10.11. Rx_MB# 127 (Network Reset)

LS10/11

LS9

LS5B/6



×

App

MCU



This MB is used by HOST MCU to reset only the Wi-Fi credentials on the device.

HOST MCU/APP LSx

MB#127 SET Command

MB#127 ACK

Acknowledgement

Response

Yes

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

127

0

Variable

Length of the

data field

-

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

10.12. Rx_ MB# 128 (Configure Static Network)

LS10/11

LS9

LS5B/6



App

MCU



This MB can be used by HOST MCU or Libre App controller to make LSx connect to specific

access point with given Static IP configuration parameters.

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Both APP developer and HOST MCU can make use of this MB to receive the static IP

configuration details (IP address, netmask, gateway, primary and secondary DNS) of Home

AP from the user and send the same to LSx.

LS module will connect to the AP with given static IP configuration details. An intermediate

response will be sent by LSx in MB#128 while the network connection status will be sent

by MB#124.

HOST MCU/APP LSx

MB#128 SET Command

MB#128 ACK

Acknowledgement

Response

Yes

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

128

NA

Variable

Length of the

data

<Data>

Data:

DATA format (Wi-Fi Mode):

<ssid::password::security::staticip::netmask::gateway::primarydns::secondarydns>

Example, If SSID of the home AP is LibreAP and Passphrase is libre@123:

DATA = LUCI_local 128 “LibreAP::libre@123::WPA PSK::192.168.1.51::255.255.255.0::

192.168.1.1::8.8.8.8::4.4.4.4"

To connect with Wi-Fi security disabled router/access point:

Example, LUCI_local 128 "DC06::NONE::NONE::192.168.1.51::255.255.255.0::192.168.1.1::

8.8.8.8::4.4.4.4"

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If the device is connected in Ethernet Mode:

DATA format (Ethernet Mode):

staticip::netmask::gateway::primarydns::secondarydns

Example, LUCI_local 128 "192.168.1.51::255.255.255.0::192.168.1.1::8.8.8.8::4.4.4.4"

Intermediate response from LSx module:

POST_SUCCESS → Static IP configuration details posted to LS module without any errors.

POST_FAILED → Failed to post Static IP configuration details to LS module.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

10.13. Rx_Message Box 134 (Ethernet Status Notifier)

LS10/11

LS9

LS5B/6



-

App

MCU

×



It is used to intimate the Ethernet Status (Link up and Link down) from MCU to LSx.

HOST MCU LSx

MB#134 SET Command

Acknowledgement

Response

No

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Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

134

NA

Variable

Length of the

data

<Data>

Data:

Data

Description

LINKUP

Ethernet cable is connected to Device

LINKDOWN

Ethernet cable is disconnected from Device

This message box is applicable only in Ethernet switch enabled products.

10.14. Rx_ MB# 142 (WAC Start)

LS10/11

LS9

LS5B/6



-

App

MCU

×



This message box is used by the HOST MCU to trigger WAC Mode in LSx device. Once WAC

is initiated, either an iOS device or device webpage can be used to configure LSx to Home

AP. The status of Network Configuration is sent by LSx over message box#143 to Host

MCU.

This message box is employed by the HOST MCU to activate the Wireless Access Control

(WAC) Mode in the LSx device. Once WAC is initiated, it opens up the possibility for

configuring LSx to connect to a Home Access Point (AP) through either an iOS device or a

device webpage.

Subsequently, LSx communicates the status of the Network Configuration through MB#143

to the HOST MCU. This status update ensures that the HOST MCU is aware of the progress

and outcome of the network configuration process.

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HOST MCU LSx

MB#142 Command

MB#143

SET

SET Response

Acknowledgement

Response

No

Yes, 143

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

142

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

0

Device will trigger the WAC.

Response Format:

Refer to MB# 143 for response.

LS10 device will support only SoftAP mode, so whenever request is received

from LS10 it will trigger the WAC without reboot.

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10.15. Tx_ MB# 143 (Network Configuration Status)

LS10/11

LS9

LS5B/6



-

App

MCU

×



This message box is used by the LSx to send update for the Network Configuration status to

the HOST MCU.

HOST MCU LSx

MB#142 Command

MB#143

SET

SET Response

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

143

NA

Variable

Length of the

data

<Data>

Data:

Data

Description

0

Initializing

1

Ready

2

Configuration Start

3

Configuration Received

4

Configuration Complete

5

Stop

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10.16. RxTx_ MB# 144 (WAC Stop)

LS10/11

LS9

LS5B/6



-

App

MCU

×



This MB is used to STOP WAC which was already triggered. HOST MCU/Phone App sends

the message over MB #144 and LSx in turn responds back with the SUCCESS/FAILURE

status of STOP WAC.

HOST MCU LSx

MB#144 SET Command

MB#144 ACK

Acknowledgement

Response

Yes

No

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

144

NA

Variable

0

-

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

Device may send WAC Stop when the WAC is triggered. This is because WAC triggered

previously is not cleared.

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10.17. RxTx_MB# 150 (Factory Reset)

LS10/11

LS9

LS5B/6



-

App

MCU



This MB is used by HOST MCU/APP requesting LSx device to reboot itself to factory settings.

HOST MCU LSx

MB#150 SET Command

MB#150 SET Response

MB#150 ACK

Acknowledgement

Response

Yes

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

150

NA

Variable

Length of Data Field

-

Response Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

150

SUCCESS /

FAILURE

Variable

Length of Data Field

-

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10.18. RxTx_MB# 151 (RSSI)

LS10/11

LS9

LS5B/6

×



App

MCU

×



RSSI is a relative value for the quality of received signal and it does not have any absolute

value. HOST MCU/APP enquiries LSx on RSSI value over this MB and LSx in turn responds

back with the current RSSI level in dBm.

LS9 and LS5B modules have single antenna (1*1) and will return only one RSSI value.

Whereas, LS6 has 2 antennas (2*2) and will return two RSSI values separated with comma.

HOST MCU LSx

MB#151 Command

MB#151

GET

Response

SET

Acknowledgement

Response

No

Yes

Command Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

151

0

Variable

0

-

Response Format:

Remote ID

Command

Type

Message

box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

151

SUCCESS/

FAILURE

Variable

Length of the

data field

<Data>

Data:

Data will be the RSSI value in dBm.

Few issues are yet to be completed in LS10.

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10.19. Tx_MB# 205 (AVS Login Status)

LS10/11

LS9

LS5B/6



App

MCU



LSx device sends the AVS Login status in the below format.

HOST MCU/APP LSx

MB#205 SET Command

Acknowledgement

Response

No

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

205

SUCESS/

FAILURE

Variable

Length of Data

Field

<Data>

Data:

Data

Description

LOGGEDIN

User is in logged in state.

LOGGINGIN

Login process is in progress.

NOLOGIN

User is in logged out state.

LOGGINGOUT

Log out process is in progress.

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The Companion App can also request the AVS Login Status as below.

HOST MCU/APP LSx

MB#205 SET Response

MB#205 GET Command

Acknowledgement

Response

No

Yes

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

205

SUCESS/

FAILURE

Variable

Length of Data

Field

<Data>

Data:

Data will be GETLOGINSTAT.

Response:

LSx will respond in the same MB#205 with the command data given above.

10.20. MB# 206 (Region)

This MB is used to read the country code, when NV-item e2pregion is set to 1 only.

For details on the e2pregion NV-Item, refer NV-Item Tech Note, available in Libre Portal.

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

206

0

Variable

Length of

data Field

<Data>

Data:

Data from NV-item e2pregion.

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Response Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

207

0

Variable

Length of

data Field

<Data>

Data:

ERROR – If country code is invalid.

10.21. Rx_MB# 209 (Bluetooth Control)

LS10/11

LS9

LS5B/6



×

App

MCU

×



Acknowledgement

Response

Notification

Yes

Yes, MB#210

Yes, MB#209 and MB#210

This message box is used to set commands to control the LibreSync Device over Bluetooth.

Command Format:

Remote

ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

209

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

LS10 & LS9

ON

Change source as bluetooth and turn ON bluetooth.

OFF

Come out of bluetooth source and turn OFF bluetooth.

ENTPAIR

Make the device discoverable and pairable. Disconnects current BT

connection if already in connected state.

SETLOCALNAME,

BTname

To give a name to the local BT device.

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GETREMOTENAME

To know the name of the remote BT device.

GETLOCALBTADDR

To know the address of the local BT device.

DISCONNECT

Disconnects the current Bluetooth connection, but the current

source is BT itself.

LS9

AUDIOFORMAT

To know the current audio format, BT device is playing.

ENTCONNECTABLE

To set the device in connectable state.

EXTPAIR

Makes the device to enter non-discoverable mode.

EXTCONNECTABLE

To set the device in not connectable state. When this

EXTCONNECTABLE command is sent, the device already paired

with, also is not connectable.

PAIREDDEV

To get a paired device list

AUTOCON

Automatically connects to the paired Bluetooth device; provided the

current source is Bluetooth.

Notification Format: (LS9)

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

209

NA

Variable

Length of the

data field

< Data>

Data:

Data

Description

btconnect,XX:XX:XX:XX:XX:XX

Notification for BT connected status.

btdisconnect

Notification for BT disconnected status.

There is no response for LS10.

Response/Notification Format for LS9:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

209

NA

Variable

Length of the

data field

<Data>

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Data:

Data

Description

btdisconnect

Notification for BT disconnected status.

LOCALBTADDR,xxxxxx. Where, xxxxx is the

MAC ID of the device.

Response for requesting a local BT address.

GETREMOTENAME,xxx (remote device name)

Response for requesting a remote BT name.

AUDIOFORMAT,x

Where, x can be:

f - when no deviceis connected (default

value)

0 - sbc codec support

2 - aac codec support

Response for requesting a current BT audio

format.

PAIREDDEV,XX:XX:XX:XX

where XX:XX , mac address of paired devices.

Response for requesting a paired device list.

Currently we are using notification on MB# 209 (LS10 → MCU). It needs to be

deprecated.

10.22. Tx_MB# 210 (Bluetooth Response)

LS10/11

LS9

LS5B/6



×

App

MCU

×



Acknowledgement

Response

Notification

No

Yes

This MB is used to notify the MCU about the Bluetooth status of LS10.

Response Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

210

NA

Variable

Length of the

data field

<Data>

Data:

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Data

Description

ON:0

Response for OFF command. It will be sent when BT is in

OFF mode.

ON:1

Response for ON command. It will be sent when BT is in

ON mode.

ENTPAIR:1

Response for ENTPAIR command. It will be sent when

pairable mode started.

LOCALBTADDR,xxxxxx.

Where, xxxxx is the MAC ID of

the device.

Response for requesting a local BT address.

GETREMOTENAME,xxx

(remote device name).

Response for requesting a remote BT name.

Notification Format:

Remote ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

210

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

BT:READY

Notification for BT is ready to accept command.

BT:2

Notification for BT connected status.

BT:0

Notification for BT disconnected status.

ENTPAIR:0

Notification for pairable mode timeout.

AUTOCONN:0

Notification for autocon mode timeout.

AUTOCONN:1

Notification for autocon mode started.

AUTOCONN:2

Notification for autocon mode is disabled.

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10.23. RxTx_MB#208 (NV Read/Write)

LS10/11

LS9

LS5B/6



APP

MCU



This MB is used by the HOST MCU to read and write the device NV-items.

HOST MCU LSx

MB#208 SET Command

MB#208 SET Response

MB#208 ACK

Acknowledgement

Response

Yes

To Read the device NV item:

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

208

SUCESS/

FAILURE

Variable

Length of Data

Field

<Data>

Data:

Data is READ_<ENVName>

Example:

READ_FriendlyName

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Response Format:

Remote

ID

Command

Type

Message

Box ID

Command Status

CRC

Data

Length

Data

0xAAAA

SET

208

SUCCESS/FAILURE

Variable

Length of

Data Field

<Data>

Data:

Data will be the value of the NV item requested.

Example:

For the request READ_FriendlyName, the value provided can be LibreSync_26c843

To Write the device NV item:

Command

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

208

SUCESS/

FAILURE

Variable

Length of

Data Field

<Data>

Data:

Data is WRITE_<ENVName,ENVValue>

E.g. WRITE_FriendlyName,OfficeSpeaker

Response

Remote

ID

Command

Type

Message

Box ID

Command Status

CRC

Data

Length

Data

0xAAAA

SET

208

SUCCESS/FAILURE

Variable

Length of

data

<Data>

Data:

Data is <ENVName:ENVValue>

E.g. FriendlyName:OfficeSpeaker

If the NV item is not available, the response is failure and the data will be 2

(LUCI error) for both READ and WRITE scenarios.

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Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

10.24. Rx_MB# 212 (SDDP Notifier)

LS10/11

LS9

LS5B/6



×

App

MCU



×

Simple Device Discovery Protocol (SDDP) is a protocol defined by Control4. SDDP is used to

discover and add all the SDDP compliant devices to the Control4 eco-system. LS enabled

devices on receipt of IP from DHCP, enables the SDDP feature and is ready to send/receive

notifications to/from the Control4 server. Control4 Server broadcasts SDDP-Messages on

the multicast address 239.255.255.250 on port 1902. LS enabled device validates the SDDP

M-Search message in the multicast address and responds to the Control4 server to

establish a session in the Control4 eco-system. The SDDP response message sent from LSx

to Control4 server is unicast message.

This MB is used to send SDDP message commands from HOST MCU to LSx.

HOST MCU LSx

MB#212 SET Command

MB#212 ACK

Acknowledgement

Response

Yes

No

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

212

Success/Failure

Variable

Length of the

data

<Data>

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Data:

Data

Description

1

NOTIFY ALIVE

Once a session is established, LSx sends “ALIVE” message to the multicast

address periodically to notify the Control4 Server that the device is online.

LSx sends the NOTIFY ALIVE message at intervals of 25 minutes.

NOTIFY IDENTIFY

NOTIFY IDENTIFY message is sent from LSx to Control4 Server when the

device is identified in the Control4 eco system. The device is identified by

user operation such as button press or any other mechanism as defined by

HOST MCU.

Transmits NOTIFY IDENTIFY message only when HOST MCU commands LSx

to do so.

2

NOTIFY OFFLINE

NOTIFY OFFLINE message is a broadcast message sent by LSx to Control4

Server.

When the device goes offline or when there is an error in connection with

Control4. If the device changes its IP address, this notification may be sent

before the change, and a NOTIFY ALIVE message must be sent immediately

after the change.

LSx transmits NOTIFY OFFLINE message only when HOST MCU commands

LSx to do so.

Acknowledgement:

An acknowledgment will be sent following the format outlined in ACK Format.

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10.25. MB# 222 (Cast OTA Update)

LS10/11

LS9

LS5B/6

×



×

APP

MCU



This MB is used by LSx to update CAST receiver package update status to HOST MCU/APP.

HOST MCU LSx

MB#222 SET Command

Acknowledgement

Response

No

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

222

NA

Variable

Length of

Data

<Data>

Data:

Data

Description

1

Downloading OTA image in background.

2

Ready for Restart.

4

Force Upgrade, HOST-MCU should get ready for immediate reboot.

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10.26. RxTx_MB# 226 (Cast Update Info)

This message box is used for two purposes:

• To update device equalizer settings (LS9 & LS10)

• To manage the Google CAST settings for TOS (Terms of Service), Share Usage Data

and Time Zone. (LS9)

LS10/11

LS9

LS5B/6



×

App

MCU



This message box is used by MCU to update device equalizer settings in LS9 and LS10. The

same settings will be notified to cast server upon receiving it from the MCU.

HOST MCU LSx

MB#226 SET Command

The same message box is also used to manage the Google CAST settings for TOS, Share

Usage Data and Time Zone in LS9.

HOST MCU LSx

MB#226 SET Command

MB#226 SET Response

(Only for TOS Share)

Acknowledgement

Response

No

Yes, for TOS Share

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Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

226

NA

Variable

Length of the

data field

<Data>

Data

Description

“EQSettings:<EQType>:

<Frequency>:<Quality>:

<gain>”

“EQSettings” is a string and EQType, Frequency, Quality Gain gives

the respective values.

<EQType> values are:

LowPass = 0

HighPass = 1

LowShelf = 2

HighShelf = 3

Peak = 4

Frequency, Quality and Gain will be their respective values.

<TOS SHARE

status>:<Timezone>

<TOS SHARE status> indicates whether TOS and usage report

share is accepted by user. It is an integer with value between 0 and

3.

0: TOS and Share is not accepted

1: Only TOS is accepted

2: Only Share is accepted

3: Both Share and TOS are accepted

<TIMEZONE> indicates the time-zone in String format. Example:

Asia/Calcutta.

APP can GET the current configuration values and can inform the

device when some settings is changed. Device will also notify the

APP when the settings is changed.

APP should strictly follow Google’s guidelines on implementing

this.

This data is used to manage the Google CAST settings for

TOS, Share Usage Data and Time Zone in LS9 only.

Google Cast MRA certification new test sheet mandated C4A

devices should have less than or equal to 1ms latency for MRA

playback. In some devices DSP includes significant amount of delay

during processing. In such cases, customer's C4A devices might fail

in Google MRA certification.

To meet Google Cast MRA requirements on MRA latency <= 1 ms

across all customer devices, MB#226 is used to update Cast

receiver about dynamic change in DSP delays.

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Data

Description

For dynamic changes, use MB#226. This will dynamically update

MRA latency values based on play mode (Movie, night mode, music,

Dolby, DTS surround etc.),

MRALatency:10000 → to set 10ms MRA latency

This data is used to manage the Google CAST settings for

TOS, Share Usage Data and Time Zone in LS9 only.

• On SET, its mandatory to provide the config values of all the fields. Say

user changes <Timezone>. on setting this, the current <TOS SHARE status> should

also be provided along with the new <Timezone>. Device reads all the fields,

compare the existing configuration and changes the updated ones.

• NV value is updated according to the message box latency values. So new changes

will be restored even after power cycles.

Response Format:

Remote

ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

226

NA

Variable

Length of

Data Field

<Data>

Data:

Data will be the TOS and Time zone values, there is no response for Cast MRA Latency.

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10.27. RxTx_MB# 229 (Get NTP Time)

LS10/11

LS9

LS5B/6



×

App

MCU

×



This message box is used to send the NTP (Network Time Protocol) time, date and current

Epoch time to HOST MCU from LSx module only when internet is active.

HOST MCU LSx

MB#229 SET Command

MB#229 SET Response

Acknowledgement

Response

No

Yes

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

229

NA

Variable

Length of the data

field

<Data>

Data:

Data

Description

date

To get the current date and time.

time

To get the current epoch time.

ntp

To get the current GMT time.

Response Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

229

NA

Variable

Length of the data

field

<Data>

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The command data is considered invalid, if it is anything other than date, time and

ntp.

Data

Description

date

LS10:

Thu 2023-06-08

06:07:41 PDT

LS9:

Thu 2023-06-08

06:07:41 GMT

If device is configured with network, LSx will send the current date.

Otherwise, LSx will send device’s default date.

time

1686231669

If device is configured with network, LSx will send the current Epoch

time (sec) otherwise, it will send device’s default Epoch time (sec).

ntp

Thursday-June- 8-

2023,13:08:07

If device is configured with network, LSx will send the current GMT

time.

NO_INTERNET

LSx sends error message “NO_INTERNET” if the internet connectivity

is not active.

NO_NETWORK

LSx sends error message “NO_NETWORK“ when WLAN or Ethernet

interface is down.

UNKNOWN_ERROR

LSx sends error message “UNKNOWN_ERROR“ for any issues other

than internet or network connectivity.

invalid

INVALID

If HOST MCU requests an invalid data.

LS9 CAST branch supports "date" and "time".

LS9 Alexa supports only "time" (Response: Thursday-June- 8-2023,13:08:07)

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10.28. RxTx_MB# 231 (Cast Serial Number)

LS10/11

LS9

LS5B/6

×



×

App

MCU



This message box is used to store the unique GCAST serial number of the device that is read

from serial.txt file. Whenever HOST MCU requests for the serial number it will be fetched

and sent to HOST MCU by LSx.

HOST MCU LSx

MB#231 GET Command

MB#231 SET Response

Acknowledgement

Response

No

Yes

Command Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

231

NA

Variable

0

-

Response Format:

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

231

NA

Variable

Length of the

data field

<Data>

Data:

Data

Description

<Serial number>,VALID

Google CAST serial number of the module. “VALID”

denotes that Google CAST is enabled in the module.

<Serial number>,INVALID

“INVALID” denotes that Google CAST is disabled in this

module. This is done for specific use cases where Google

Cast is disabled dynamically in the module.

Get in touch with Libre FAE if you have this use case.

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10.29. RxTx_MB# 233 (MIC Control)

LS10/11

LS9

LS5B/6



App

MCU

×



This MB is used to send MIC control messages between LSx and HOST MCU.

HOST MCU LSx

MB#233 SET Command

MB#233 SET Response

Acknowledgement

Response

No

Yes

Command

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

233

NA

Variable

Length of

Data

<Data>

Response

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

233

Success /

Failure

Variable

Length of

Data

<Data>

Command & Response Data:

Command Data

Description

Response Data

Description

START_MIC

Indicates LSx to start

capturing the voice.

Typical scenario would

be button press or tap or

when MIC detects "Alexa"

key word.

MIC_STARTED

(Not

implemented

yet)

Indicates to HOST MCU

that LSx has started

listening to user's voice,

HOST MCU can use this

command to show LED

indication.

STOP_MIC

Indicates LSx to stop

MIC_STOPPED

Indicates to HOST MCU

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Command Data

Description

Response Data

Description

capturing the voice.

Typical scenario would

be button press or when

user releases the tap or

when MIC detects

silence.

(Not

implemented

yet)

that LSx has stopped

listening to user's voice,

HOST MCU can use this

command to stop LED

indication.

ENABLE_MICS

HOST MCU commands

LSx to move the device

from privacy mode to

ready mode.

MICS_ENABLED

Send by LSx as a

confirmation message to

HOST MCU, that the

device is in ready mode.

DISABLE_MICS

HOST MCU commands

LSx to move the device to

PRIVACY mode.

MICS_DISABLED

LSx sends as confirmation

message to HOST MCU,

that the device is in

privacy mode.

STOP_ALERT

Indicates LSx to stop the

alarm trigger. Typical

scenario would be button

press or when user

releases the tap.

-

10.30. MB# 234 (AVS APP Service)

This MB is used for AVS login/logout, Language Change transactions between LSx device

and Companion APP.

Case 1: AVS Login through companion APP using MB#234

1. When user access Login with Amazon (LWA) icon in the companion APP, APP will send

the metadata request to the LS Device over MB #234 in the following format. (Login session

started from here):

Companion App → LS device

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

GET

234

SUCESS/

FAILURE

Variable

Length of

Data Field

DEVICE_METAD

ATA_REQUEST

2. LS device will form the metadata and send it back to the companion app in the following

format:

LS device → Companion App

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Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

234

SUCESS/

FAILURE

Variable

Length of

Data Field

<Data>

data: " {"Title":"DEVICE_PROVISIONING_INFO","Window

CONTENTS":{"PRODUCT_ID":"XXXXXXXXX","DSN":"XX:XX:XX:XX:XX:XX","SESSION_ID":"123

456789","CODE_CHALLENGE":"XXXXXXXXXXX","CODE_CHALLENGE_METHOD":"S256","LO

CALE":"en-US"}} "

S256

A Base64url encoding of your code verifier's SHA256

hash. The Base64url encoded string should not contain

the following characters: "=", "+", or "/"

Title

On every metadata request the value of Title is constant

{e.g., "DEVICE_PROVISIONING_INFO"}

PRODUCT_ID

The value of PRODUCT_ID is Alexa Product ID of the LS

Device

DSN

MAC id of the LS Device

SESSION_ID

Random generated number which remains same for the

current active session. Session_ID changes for the new

session

CODE_CHALLENGE

Random string generated by the product which is

hashed (SHA256) and handed off to the companion app.

The string should be between 43 and 128 characters

long and composed of characters from the URL and

filename-safe alphabet ([A-Z], [a-z], [0-9], "-", "_ ", ".",

"~")

CODE_CHALLENGE_METHOD

The method used to derive the code challenge. AVS

requires SHA-256. So, the value of

ODE_CHALLENGE_METHOD is S256

LOCALE

Supported language

The Companion App uses this information to interact with AVS cloud.

Refer to the link for transaction details between Companion App and AVS cloud:

https://developer.amazon.com/en-US/docs/alexa/alexa-voice-service/authorize-

companion-app.html

3. The user is redirected to an Amazon login page and prompted to enter their Amazon

credentials and consent.

4. After user enters their Amazon credentials and consent, the companion APP interacts

with AVS cloud and should send below information to the LS Device:

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- Authorization Code

- Client ID

- Redirect URI

Companion App → LS device.

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

234

SUCESS/

FAILURE

Variable

Length of

Data Field

<Data>

data:

"AUTHCODE_EXCH:

{"AUTH_CODE":"XXXXXXXX","CLIENT_ID":"XXXXXXXXXXXXXX","REDIRECT_URI":"XXXXXXX

XXXXXX","SESSION_ID":"123456789"}"

5. The LS device uses the above Authorization Code, Client ID, Redirect URI information to

interact with AVS cloud via Login with Amazon and receive refresh token and access token.

6. LS device sends the ACCESS_TOKENS_STATUS to the App in below format (Login session

completes here):

LS device → Companion App

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

234

SUCESS/

FAILURE

Variable

Length of

Data Field

<Data

data: "{"Title": "ACCESS_TOKENS_STATUS", "status": true/false}"

If status value is true: LWA success

If status value is false: LWA failed

7. The app must get the login status by sending AVS Login status request to the LS device

over MB#205. Refer to MB #205 for more information.

8. The LS Device uses the access token to interact with AVS and it will refresh the token

once its expired.

Case 2: Log out scenario using MB-234

1. Once the user press sign-out button from the companion app, companion app will send

the log out message to the LS device in the following format.

Companion App → LS device

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Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

234

SUCESS/

FAILURE

Variable

Length of

Data Field

SIGN_OUT

The Companion APP should read the LOGOUT status from MB #205.

Case 3: Change the language from companion app using MB-234

1. When user changes the language from companion app, the APP should send the below

information to the LS device:

Companion App → LS device

Remote ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

234

SUCESS/

FAILURE

Variable

Length of

Data Field

data

data: "UPDATE_LOCALE:Supported Language values"

Supported Language values: en-US, en-GB, en-AU, en-NZ, de-DE, fr-FR, it-IT, es-ES, en-IN, ja-

JP.

10.31. Tx_MB# 240 (AVS Client Status)

This MB is used to communicate current AVS status to HOST MCU. On receipt of the

message, HOST MCU should drive the LEDs as mandated by Amazon.

HOST MCU LSx

MB#240 SET Command

Command

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

240

NA

Variable

Length of

Data

<Data>

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Data:

Data

Description

READY

System is ready to accept commands

LISTENING

MIC is turned ON for recording

THINKING

MIC is turned OFF

SPEAKING

Speech Started

TIMEOUT

Response from Amazon server is empty or

there was an error in communicating the

voice request

NOLOGIN

User has not logged into the device using the

amazon account

PRIVACY MODE

System is in Privacy mode

ALERTTRIGERRED

Alarm is Triggered

NOTIFICATIONMODE

Notifications are in queue

ALEXATRIGGERED

Whenever the system detects Alexa wake-

word. Host-MCU need not to respond with

any indication for this command.

NOINTERNET

Whenever the end user asks for a query and if

the system loses the internet connection.

DNDON

Do Not Disturb mode is Turned-On.

CALLINBOUNDRINGING

Incoming Call Alert.

CALLINBOUNDRINGING_ONENUM

Incoming One Number Call Alert.

CALLOUTBOUNDRINGING

Outgoing Call Alert.

CALLOUTBOUNDRINGING_ONENUM

Outgoing One Number Call Alert.

CALLCONNECTED

Call Successfully Connected

CALLCONNECTED_ONENUM

One Number Call Successfully Connected

CALLDISCONNECTED

Call Disconnected

CALLDISCONNECTED_ONENUM

One Number Call Disconnected

10.32. RxTx_MB# 246 (Alexa UI)

This MB is used to update the Alert List and other UI information to HOST MCU from LSx.

HOST MCU LSx

MB#246 SET Command

MB#246 SET Response

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Command (Network Client / HOST-MCU to LSx)

Remote

ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

GET

246

NA

Variable

Length of

Data

<Data>

Data:

Data is GET_ALERTS_LIST.

Response (LSx to HOST-MCU / Network Client)

Remote

ID

Command

Type

Message-

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

GET

246

SUCCESS /

FAILURE

Variable

Length of

JSON Data

<Data>

Data:

Data will be JSON information.

Example of GET_ALERTS_LIST Response

{

"ALERTS_LIST":{

"activeAlerts":[

{

"scheduledTime":"2017-11-02T10:48:05+0000",

"token":"amzn1.as-

ct.v1.Domain:Application:NotificationsV4#DNID#f067d84d-619c-3527-99fc-

5515cdde1ef0",

"type":"TIMER"

}

],

"allAlerts":[

{

"scheduledTime":"2017-11-02T10:50:00+0000",

"token":"amzn1.as-

ct.v1.Domain:Application:NotificationsV4#DNID#d4e98dfc-ebc3-338a-bb55-

97df88bf4883",

"type":"ALARM"

},

{

"scheduledTime":"2017-11-02T10:48:05+0000",

"token":"amzn1.as-

ct.v1.Domain:Application:NotificationsV4#DNID#f067d84d-619c-3527-99fc-

5515cdde1ef0",

"type":"TIMER"

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}

]

}

where,

• ALERTS_LIST: Title of Json.

• "allAlerts”: Key/value pairs for allAlerts object

o allAlerts. token: Alert token returned by Alexa when the alert was

set.

o allAlerts. type: Identifies the alert type. Accepted Values: TIMER,

ALARM.

o allAlerts. scheduledTime: Time the alert is scheduled in ISO 8601

format.

• "activeAlerts”: Key/value pairs for activeAlerts object

o activeAlerts. token: The token for the alert that is currently firing.

o activeAlerts. type: Identifies the alert type. Accepted Values: TIMER

or ALARM

o activeAlerts. scheduledTime: Time the alert is scheduled in ISO 8601

format.

Additional JSON Information

Example New Alert JSON Format

{

"NEW_ALERT":{

"scheduledTime":"2017-11-02T10:48:05+0000",

"token":"amzn1.as-

ct.v1.Domain:Application:NotificationsV4#DNID#f067d84d-619c-3527-99fc-

5515cdde1ef0",

"type":"TIMER"

}

Example Alert Removed JSON Format

{

"ALERT_REMOVED":{

"scheduledTime":"2017-11-02T10:48:05+0000",

"token":"amzn1.as-

ct.v1.Domain:Application:NotificationsV4#DNID#f067d84d-619c-3527-99fc-

5515cdde1ef0",

"type":"TIMER"

}

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10.33. RxTx_MB# 247 (Enable Speech Tone)

LS10/11

LS9

LS5B/6

×



App

MCU

-

This message box allows remote devices to know the "EnableSpeechTone" ENV status and

remote devices can set the ENV-item "EnableSpeechTone" to value "1" or "0".

To SET the ENV item:

HOST MCU LSx

MB#247 SET Command

MB#247 SET Response

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

SET

247

NA

Variable

Length of

Data

<Data>

Data:

Data

Description

0

Will disable Alexa speech start and stop tones and EnableSpeechTone NV-

item will be set to “0”.

1

Will enable Alexa speech start and stop tones and EnableSpeechTone NV-

item will be set to “1”

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Response Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET / GET

247

NA

Variable

Length of

JSON Data

-

Data:

To know the ENV status

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data Length

Data

0xAAAA

GET

247

NA

Variable

Length of

Data

-

Response Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET / GET

247

NA

Variable

Length of

JSON Data

<Data>

Data:

Data

Description

0

Will disable Alexa speech start and stop tones and EnableSpeechTone NV-

item will be set to “0”.

1

Will enable Alexa speech start and stop tones and EnableSpeechTone NV-

item will be set to “1”

10.34. MB# 248 (AVS Custom Speech)

This MB is added to enable "alarm snooze functionality" through button. This will work

along with the conventional "Alexa Snooze".

Command Format

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

248

NA

Variable

0

<Data>

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10.35. Tx_MB# 494 (Cast Setup Started)

LS10/11

LS9

LS5B/6

×



×

APP

MCU

×



In this MB, LS9 CAST-Enabled Device initiates a notification by sending a CAST SETUP

started signal to the HOST MCU. On receiving this message, HOST MCU should change the

source to WiFi/Network source, wake the peripheral interfaces in case the device is in

standby mode to play the audio test tone during the Google Home APP setup. If the device’s

audio path is assigned to external sources, the user might not hear the audio test tone

played by the LS9, potentially causing issues during the setup process. Hence, this

notification serves the purpose of changing the audio path back to LS9.

MCU LSx

MB#494 SET Command

Acknowledgement

Response

No

Command Format:

Remote

ID

Command

Type

Message

Box ID

Command

Status

CRC

Data

Length

Data

0xAAAA

SET

494

NA

Variable

0

Data

Data:

Data is <CASTSetupStart>.