Bluetooth® LE Audio Solutions


Conetents

Introduction


By using less power and less bandwidth yet still enabling high-quality audio transmissions, LE Audio is undoubtedly an improvement on Bluetooth Classic and Bluetooth LE. Backed by Bluetooth 5.2, it opens up many new opportunities for audio device manufacturers, especially with the right SoC solution. Telink’s multiprotocol TLSR9 chip is in compliance with not only the Bluetooth 5.2 standard but also EDR, BR, and LE, and can provide all of the aforementioned LE audio applications. Telink offers ready-to-use development kit for immediate evaluation.


Resources



Part Number Product Brief Demo Files Dev Kit Hardware Design Guide Reference Design
TLSR9 TLSR9 Series Product Brief CIS Demo
Audio Sharing Demo
B91 Generic Starter Kit B91 Hardware Design Guideline B91 Development Board


Bluetooth® LE Audio


Bluetooth LE 5.2 Enables New Audio Use Cases

  • Two types of ISO transfers defined in Bluetooth 5.2
    • Connection-oriented: logical transport referred as Connected Isochronous Stream (CIS)
    • Connection-less: logical transport referred as Broadcast Isochronous Stream (BIS)
    • ISO Data channel allows transfer of isochronous data between a Bluetooth LE central and one or more Bluetooth LE peripherals
    • Used for new application area for audio streaming and audio broadcasting
    • Can also be used for non-audio time-bounded data
  • Introduce a new high-quality, low-power LC3 audio codec


TWS Earbuds Based on Connected Isochronous Streams

Multi-Stream Audio enables the transmission of multiple, independent, synchronized audio streams between an audio source device and one or more audio sink devices.

A Connected Isochronous Group (CIG) is created by the master and it can include one or more Connected Isochronous Streams (CISs). A CIS is a point-to-point, data transportation stream between a master and a certain slave, and is a bidirectional communication protocol with acknowledgment.

TWS_Based_on_CIS



Broadcast Audio for Audio Sharing

Audio Sharing enables an audio source device to broadcast one or more audio streams to an unlimited number of audio sink devices.

A Broadcast Isochronous Group (BIG) is created by an Isochronous Broadcaster and it can include one or more Broadcast Isochronous Streams (BISs). A BIS is a one-to-many data transportation stream. It uses the broadcast packet transportation mechanism without acknowledgment.

Audio_Sharing


Demo Material List

B91-Generic-Starter-Kit

Item S/N Product Name Qty Description
1 TLSR9518ADK80D B91 Development Board 1 including jumpers
2 TLSRGSOCBK100B TLSR9 DEV KEY 1 JTAG BURING EVK, including DuPont wires
3 TLSRGSOCBK56B Telink Burning Board 1 SWS BURING EVK, including DuPont wires
4 Whip Antenna 1 2.4Ghz antenna
5 USB cable 1 USB A to mini USB

Remarks: This demo requires multiple B91 Development Boards and USB cables. Please refer to the detailed introductions under each demo guide.


PC installed with



Prerequisite for B91 Development Boards

Top View and Function Layout

B91_Dev_Board_LE_Audio_DMIC



TWS Earbuds Based on CIS Demo


The demo below uses three Telink B91 Development Boards to simulate a master device and two Slave devices, respectively. It features a two-channel stereo link with sampling rates of 16kHz/48kHz, bit depth of 16bits/sample, and encoded bit rate of 32kbps/96kbps. Developers can follow the steps to program the dev boards, make the correct configuration and and listen to the audio streams.

Configuring the CIS Demo

You can use the prebuilt binaries for the following demo testing. Please contact Telink sales to obtain the demo binary files.

  • 16kHz Sampling Rate
    – Eagle_CIS_Audio_Demo_LineIn_Master_16kHZSample.bin - the master device with audio source input from Line In
    – Eagle_CIS_Audio_Demo_Slave_16kHZSample.bin - the Slave device
  • 48kHz Sampling Rate
    – Eagle_CIS_Audio_Demo_LineIn_Master_48kHZSample.bin - the master device with audio source input from Line In
    – Eagle_CIS_Audio_Demo_Slave_48kHZSample.bin - the Slave device

It requires the latest TELINK BDT tool to program the target boards.

Step 1: Connect the B91 Development Board with Telink Burning Board via DuPont wires, then plug the Telink Burning Board into the USB port on the PC.

B91_Dev_Board_Programming

Step 2: Launch the Telink BDT on PC, and program the B91 Development Boards respectively.

Step 3: To configure the MAC address for the master and slave devices, launch the “Memory Access” tool in the Telink BDT.

BDT_Memory_Access

Step 4: Write the 6-byte MAC address in the specified format to the specified location in FLASH.

  • Master: Write CC CC CC CC CC CC to the address 0xF0000 in FLASH.

CIS_Demo_Master_MAC

  • Slave: Write CC 01 CC CC CC CC and CC 02 CC CC CC CC to the address 0xFF000 in FLASH.

CIS_Demo_Slave_MAC_1
CIS_Demo_Slave_MAC_2

  • Please make sure that the highlighted parts of the MAC address are the same.


TWS_Based_on_CIS_Demo

Step 5: Power on the B91 Development Boards. The Master board enters the scan mode, and the Slave boards enter the broadcast mode automatically.

Step 6: Press the SW4 button on the Master board to pair with one of the Slave boards. Blue LED indicators on both Master board and Slave board light up after the pairing completion.

Step 7: Press the SW4 button on the Master board to pair with another Slave board. Green LED indicator on Master board and blue LED indicator on the Slave board light up after the pairing completion.

Step 8: The master will automatically make service discovery when the connection is successful. After the corresponding service is found, the CIS will be created automatically and the three boards indicate with a white LED when a connection is successful.



Recording and Playback Test - CIS Demo

Step 1: Connect your PC or mobile phone to the Line In port on the Master board. You can listen to the music from the Line Out ports on the Slave boards while playing it on the PC or the phone.

Audio_Playback_CIS

Step 2: Connect the Slave boards to PCs through USB cables respectively. Launch the Audacity software on PC, select “Telink LE Audio” as the audio input, and click “Recod” to record the audio data.

CIS_Audacity_Record

CIS_Audacity_Record



Broadcast Audio for Audio Sharing Demo



The demo below uses four Telink B91 Development Boards to simulate a master device and multiple Slave devices respectively. Developers can follow the steps to program the dev boards, make the correct configuration and listen to the audio.

Configuring the Audio Sharing Demo

You can use the prebuilt binary for the following demo testing. Please contact Telink sales to obtain the demo binary files.

  • LE_Audio_Demo_BIS_LineIn_Master.bin - the master device with audio source input from Line In
  • LE_Audio_Demo_BIS_Sync.bin - the Slave device

It requires the latest TELINK BDT tool to program the target boards.

Step 1: Connect the B91 Development Board with Telink Burning Board via DuPont wires, then plug the Telink Burning Board into the USB port on the PC.

B91_Dev_Board_Programming

Step 2: Launch the Telink BDT on PC, and program the B91 Development Boards respectively. There are one Master and multiple Slave devices. Two Slave boards are used in the following demo. But the users can have as many Slave boards as they want.

Audio_Sharing_Demo

Step 3: Power on all the B91 Development boards, the Slave boards will automatically synchronize the broadcast data of the Master board. After the synchronization is successful, the green LED indicators on Slave boards light up.



Recording and Playback Test - Audio Sharing Demo

Step 1: Connect your PC or mobile phone to the Line In port on the Master board. You can listen to the music from the Line Out ports on the Slave boards while playing it on the PC or the phone.

Audio_Playback_BIS

Step 2: Connect the Slave boards to PCs through USB cables respectively. Launch the Audacity software on PC, select “Telink LE Audio” as the audio input, and click “Recod” to record the audio data.

CIS_Audacity_Record

CIS_Audacity_Record