Serial microphone using arduino-pico on an RP2040 and INMP441 MEMS mic
Current implementation uses the following wiring, so it fit's nicely on top of a RP2040-zero:
| RP2040 | INMP441 |
|---|---|
| 1 | L/R |
| 3 | SCK |
| 4 | WS |
| GND | GND |
| 3V3 | VDD |
| 29 | SD |
Connect RP2040 pin 2 and 4 together, so the mic connections align nicely with the zero (WS connects to both RP2040 pin 2 and 4).
The sketch outputs its 24 bits samples in 3 bytes, in hex format over the serial port. Using xxd this can be piped to ALSA:
$ cat /dev/ttyACM0 | xxd -r -p | aplay -r16000 -c1 -fS24_3BE