[IDEA] Change GPIO state on mpd play / stop

[TheOldPresbyope]

Thanks to this, I finally got around to looking at the /proc/asound virtual file system maintained by ALSA. Cool beans.

At first blush, the generalization would have to include the possibility that it's not card0 that's been selected. Case in point, my USB DAC is card1 (because card0 is the "onboard audio device").

Regards,
Kent