USB Audio device

[marcdraco1-gif]

Philip Schatzmann (@pschatzmann I think) has posted an update to TinyUSB (Adafruit library) to work as a speaker and (crucially for me) a microphone device too for the Pico.

I've got a project in production that really could use "freedom" from custom ICs as it's anyone's guess how long they will be around for. The Pico is easy to implement with a digital mic like the INMP441 with streaming audio this would be an amazing addition.

[maxgerhardt]

Let's be as clear as possible and add some concrete references:

• suport for isosynchronous USB audio devices was added for TinyUSB in Rp2040 - ISO API to make Audio work / Merge to master hathach/tinyusb#2847 and related
• this has since been released in TinyUSB 0.19.0
• mainline Adafruit TinyUSB has not integrated the USB audio device capability yet in an abstracted way (USBAudio for rp2040 adafruit/Adafruit_TinyUSB_Arduino#511)
• The original author of the PR also has a forked Adafruit TinyUSB version with audio example sketches:
  • https://github.com/pschatzmann/Adafruit_TinyUSB_Arduino/tree/Audio
  • https://github.com/pschatzmann/Adafruit_TinyUSB_Arduino/tree/Audio/examples/Audio
• this core already integrates Adafruit TinyUSB (mainline), currently standing at Adafruit TinyUSB 3.7.2

The way I see it, someone has to make a PR that will add the Audio devices into Adafruit TinyUSB, then this can be easily used by this Arduino core. Or use the forked Adafruit TinyUSB at your own risk.