Full-duplex audio streaming solution based on STMicroelectronics STM32WB5MMGH6TR ultra-low power Bluetooth module
STMicroelectronics' SL-CNWLC01104V1 solution provides two-way wireless audio communication with high-quality audio and extremely low power consumption, making it ideal for smart home and industrial applications such as audio entertainment and gaming, wireless speakers, PC peripherals, headsets, and wearables Device for playing music from your smartphone and voice controlling your TV remote.
The speech processing chain starts with the MP34DT06J digital MEMS microphone, which converts the input audio into pulse density modulation (PDM) format. The ultra-low-power STM32WB series MCUs with embedded Bluetooth® low-energy certified transceivers continue to further convert and compress the digital audio signal in Opus format, then send the wireless codec packets to the same system for decoding and subsequent over USB Audio output interface for streaming.
This solution for streaming Opus format audio over Bluetooth® 5.0 full duplex requires setting up two nodes with identical hardware, including the STM32WB5MM-DK discovery board (a development board with the STM32WB5M module). One node is configured as a central node and the other as a peripheral node, and each node can act as both a transmitter and a receiver.
Once the FP-AUD-BVLINKWB1 STM32Cube function package with the necessary hardware drivers and encoding software is loaded onto the Nucleo-64 development board microcontroller and the node is configured correctly, the audio captured by the Tx side digital MEMS microphone is compressed and Through wireless pairing with the Rx side, the received audio is decompressed and sent over USB configured as an audio output interface.
The STM32WB5MM-DK Discovery Kit is designed as a complete demonstration and development platform for the STMicroelectronics STM32W5MMG module based on the Arm® Cortex®-M4 and Arm® Cortex®-M0+ cores. The STM32 device is a multi-protocol wireless ultra-low power device that embeds a powerful ultra-low power radio and is compliant with the Bluetooth® Low Energy (BLE) SIG specification v5.2 and IEEE 802.15.4-2011.
The Discovery Kit's hardware features allow users to develop their applications: Audio, USB, User Button and Bluetooth® Low Energy. Expansion connectors allow easy connection of ARDUINO® boards for specific applications. ST-LINK/V2-1 is integrated on the board as an embedded in-circuit debugger and programmer for STM32 MCU and USB virtual COM port bridge.
FP-AUD-BVLINKWB1 is an STM32Cube function package that can perform full-duplex voice streaming or stereo music streaming over BLE using advanced Opus compression algorithms.
The application runs on a P-NUCLEO-WB55 or STM32WB5MM-DK connected to the X-NUCLEO-CCA02M2 and includes drivers and middleware for BLE and digital MEMS microphones. It also includes the full Opus audio codec (v 1.3) as third-party middleware for performing bidirectional and synchronous audio streaming between two STM32WBs.
The peripheral module can also communicate in full-duplex mode (two-way audio at 16 kHz) with a mobile device running the STBLESensor application, or receive stereo music at 48 kHz from the same application. For example, the proposed combination of this software with STM32WB and ST devices can be used to develop wireless audio communication systems for smart home or wearable applications. The Opus algorithm provides the flexibility to achieve high audio quality even at low bitrates, and the STM32WB has low-power capabilities, allowing the development of applications with extremely low power consumption.
Original factory related web pages
SL-CNWLC01104V1 - Streaming full-duplex audio over Bluetooth Low Energy - STMicroelectronics
Development board documentation tools software, etc.:
STM32WB5MM-DK - Discovery kit with STM32WB5MMG MCU
Scenario application diagram
Development board photos
Scheme diagram
Core Technology
1. STM32WB55VGY ultra-low power dual-core Arm Cortex-M4 MCU 64 MHz, Cortex-M0+32MHz, with 1 Mbyte flash memory, Bluetooth LE 5.2, 802.15.4, Zigbee, thread, USB, LCD, AES-256
2. The microcontroller simplifies bidirectional communication with the DSP instruction set for fast audio signal processing and embedded RF radio (Bluetooth® Low Energy v5.0 compatible), and the architecture is specifically designed for lowest power consumption.
3. MP34DT06J-MEMS stereo digital microphone. This extremely low-power microphone outputs high-quality, low-noise digital audio signals that can be quickly converted and transmitted through appropriate wired or wireless protocols (such as Bluetooth® low energy).
4. Easy-to-implement, low-cost and highly compact full-duplex communication solution
5. Bluetooth® low energy SIG specification v5.0 compatible
6. OPUS format for efficient speech audio coding
7. Extremely low power consumption, very suitable for portable battery-powered applications
Solution Specifications
1. STM32WB5MMG ultra-low power certified 2.4GHz wireless module
2. 2.4 GHz RF transceiver supporting Bluetooth® specification v5.0 and IEEE 802.15.4-2011 PHY and MAC
3. Dedicated Arm® 32-bit Cortex® M0+ CPU for real-time radio layer
4. Integrated PCB antenna or package for SMA connector
5. CR2032 battery onboard socket
6. Supports multiple integrated development environments (IDEs), including IAR™, Keil®, GCC-based IDE, Arm® Mbed™
7. 2 MP34DT06J digital MEMS microphones
8. Firmware for full-duplex communication via Bluetooth® Low Energy using the Opus codec
9. BlueVoiceOPUS customized BLE audio profile, including API for leveraging advanced Opus features (source code provided)
10. Third-party Opus v1.3 (can be downloaded from https://www.opus-codec.org) middleware
11. Digital audio signal collection and processing
12. Play audio output via USB
13. Example implementation suitable for STM32WB5MM-DK
