Audio Module Configuration
The audio module config options are: Codec2 Enabled, PTT GPIOGPIO (General Purpose Input/Output). An uncommitted digital signal pin on a device., Audio Bitrate/Codec Mode, I2S Word Select, I2S Data IN, I2S Data OUT and I2S Clock. Audio Module config uses an admin message sending a ConfigModule.Audio protobufProtobuf (Protocol Buffers). A method developed by Google for serializing structured data, used in Meshtastic for efficient communication protocol between devices..
With this experimental module, you can add a digital I2S microphone and speaker to any ESP32ESP32A chipset of microcontroller made/designed by Espressif, used by a number of devices. Higher power usage than nRF52, but often cheaper and supports Wi-Fi if desired. device that has a SX128x radio and operates on the 2.4 GHz ISM Band. The Sub-1GHz bands are not wide enough to support continuous audio packets on the mesh, even in the Short and Fast modes. Right now, the only devices supported are the LilyGo TLora 2.1-1.8 and TLora T3S3 boards. The module has been designed for channels with 2kbit / sec of bandwidth or greater.
Required additional hardware:
- Max98357 - I2S 3W Class D Amplifier
- MSM261S4030H0 - I2S MEMS Low Noise Single Microphone
Audio Module Config Values
Codec2 Enabled
Enables the audio module.
PTT GPIO
The GPIOGPIO (General Purpose Input/Output). An uncommitted digital signal pin on a device. to use for the Push-To-Talk button. The default is GPIOGPIO (General Purpose Input/Output). An uncommitted digital signal pin on a device. 39 on the ESP32ESP32A chipset of microcontroller made/designed by Espressif, used by a number of devices. Higher power usage than nRF52, but often cheaper and supports Wi-Fi if desired..
Audio Bitrate/Codec Mode
The bitrate to use for audio. The default is CODEC2_700B. The available options are:
- CODEC2_DEFAULT
- CODEC2_3200
- CODEC2_2400
- CODEC2_1600
- CODEC2_1400
- CODEC2_1300
- CODEC2_1200
- CODEC2_700B
- CODEC2_700
I2S Word Select
The GPIOGPIO (General Purpose Input/Output). An uncommitted digital signal pin on a device. to use for the WS signal in the I2S interface.
I2S Data IN
The GPIOGPIO (General Purpose Input/Output). An uncommitted digital signal pin on a device. to use for the SD signal in the I2S interface.
I2S Data OUT
The GPIOGPIO (General Purpose Input/Output). An uncommitted digital signal pin on a device. to use for the DIN signal in the I2S interface.
I2S Clock
The GPIOGPIO (General Purpose Input/Output). An uncommitted digital signal pin on a device. to use for the SCK signal in the I2S interface.
These Pins comprise an I2S digital audio interface. Meshtastic uses it in monoaural mode. The software will use the logical 'LEFT' Stereo channel for the microphone and the logical 'RIGHT' Stereo channel for the speaker, so configure your breakouts accordingly. Audio is Half-Duplex, so we can re-use part of the pins for a bi-directional configuration. There's no default pin assignment, setting these is mandatory.
Audio Module Config Client Availability
- Android
- Apple
- CLI
- Web
Android
Audio Config options are available for Android.
- Open the Meshtastic App
- Navigate to: Settings > Audio
Apple
Audio module config is not available on iOS, iPadOS and macOS.
CLI
All audio module config options are available in the python CLI. Example commands are below:
| Setting | Acceptable Values | Default |
|---|---|---|
| audio.codec2_enabled | true, false | false |
| audio.ptt_pin | GPIO Pin Number 1-39 | Default of 39 is Unset |
| audio.bitrate | CODEC2_DEFAULT CODEC2_3200 CODEC2_2400 CODEC2_1600 CODEC2_1400 CODEC2_1300 CODEC2_1200 CODEC2_700B CODEC2_700 | CODEC2_DEFAULT |
| audio.i2s_ws | GPIO Pin Number 1-34 | no Default |
| audio.i2s_sd | GPIO Pin Number 1-39 | no Default |
| audio.i2s_din | GPIO Pin Number 1-34 | no Default |
| audio.i2s_sck | GPIO Pin Number 1-34 | no Default |
Because the device will reboot after each command is sent via CLI, it is recommended when setting multiple values in a config section that commands be chained together as one.
meshtastic --set audio.codec2_enabled true --set audio.bitrate CODEC2_1400
meshtastic --set audio.codec2_enabled true
meshtastic --set audio.codec2_enabled false
meshtastic --set audio.i2s_ws 7
meshtastic --set audio.i2s_din 28
meshtastic --set audio.ptt_pin 37
meshtastic --set audio.bitrate CODEC2_DEFAULT
meshtastic --set audio.bitrate CODEC2_1400
Web
All audio module config options are available in the Web UI.
GPIOGPIO (General Purpose Input/Output). An uncommitted digital signal pin on a device. access is fundamentally dangerous because invalid options can physically damage or destroy your hardware. Ensure that you fully understand the schematic for your particular device before trying this as we do not offer a warranty. Use at your own risk.
This module requires attaching a peripheral accessory to your device. It will not work without one.