AudioKit and Haut‐de‐Forme board
The ESP32-WROOM and ESP32-WROVER modules have been transformed in audio-specific modules with an integrated codec by Ai-Thinker called the ESP32 A1S. It is now easily found pre-assembled on a nifty audio development board usually called "ESP32 AudioKit", with a few different revisions available on popular Chinese websites.
The board is quite well made and is supported by another awesome library called arduino-audio-driver that integrates perfectly with AudioTools and ESP32-A2DP library. Two issues remain with the board however : the DCD pin of the onboard CP2102 UART chip is not easily accessible (and not grounded) and the interface itself is sensitive to fluctuations in the 5V supply of the USB, which I have observed to happen, because of how it is wired.
To remedy those hardware shortcomings, two options exist :
- Combining an LDO breakout board (5V->3V3, recommended 0.8A output and some ESD protection diodes ) such as the ones based on the ever popular AMS1117-3V3 or even some switched break-out 3V3 power supplies, as long as their output voltage is relatively "clean", with a CP2102 or CP2104-based USB-UART breakout board with accessible DCD pin. A bit of soldering and/or wires is necessary, correct connections are available on this wiki page.
- Buying/Copying the provided "Haut-de-forme" board (Top-Hat, in French) which essentially integrates a CP2102 UART interface with an LDO in a convenient form factor that mounts quite low on top of the AudioKit board.
![/img/LDOBoard.jpg|LDO breakout board]]
A common AMS1117 LDO breakout board
A render of the Haut de Forme board
In any of the scenarios it will be necessary to edit the VID and PID on the UART interface in order for it to be recognized by the car. Same instructions apply as for the more DIY solution if using a CP2102 or CP2104. <- Needs to be rewritten