@anichang Hi Anichang, interesting question. I'm into audio.
Check this out - nice audio quality: https://twitter.com/ksasao/status/972853730453241857
GPIO36 seems to be the approach taken so far for audio input - also by macsbug:
Perhaps for your purpose with the external mic and the PAM board you were talking about using the I2S (or IIS) pins - IIS_IN (G34) and (IIS_OUT (G15) ???
I don't think they are being used by anything obvious on the M5Stack - (screen,buttons,TF card)......
The M5Stack guys recently demoed audio playback using I2s on twitter recently.... i gather they output using the DAC (g25). Using Python: https://twitter.com/M5Stack/status/972058080081883136
Anyone else got any info on audio input?