"pisound: Reading card info failed: -22"

Ok, thank you, it looks like the communication with Pisound via SPI is still failing.

Some more things to try could be:

  • Try it on another Raspberry Pi unit, if you have access to one.
  • Try a different power supply (but with Pi 4 and USB-C, we haven’t yet witnessed any problems caused by power supplies)
  • If you don’t have another Raspberry Pi, you could use a test script to verify its own GPIO pins are working fine.
  • Try reflashing the Pisound firmware - it’s done via SPI too, but it’d be interesting to see whether the firmware flashing program manages to communicate with the chip on Pisound.

Occasionally, there’s a chance there was some electrostatic discharge event during handling of Pisound, damaging the microcontroller on Pisound, in that case, you should send it back to us for a replacement unit.