Due to my soundcard already using GPIO 20,21 I could circumvent the error message by simply wiring the two switches to GPIO 16, 26. However, I still get an error message, now saying that the sound device is invalid.
Expression ‘parameters->channelCount <= maxChans’ failed in ‘src/hostapi/alsa/pa _linux_alsa.c’, line: 1514
Expression ‘ValidateParameters( outputParameters, hostApi, StreamDirection_Out ) ‘ failed in ‘src/hostapi/alsa/pa_linux_alsa.c’, line: 2825
Invalid audio device #1
Any clue on this?