x400 audio card

Currently in Phoniebox

Issues

• speakers don't mute when headphone is plugged in (see https://wiki.geekworm.com/X400)

Installation

http://www.suptronics.com/xseries/x400.html https://www.hackster.io/FunguyPro/how-to-use-supstronics-x400-expansion-board-68f956

• Input Voltage: 6V to 24Vdc converted to 5V, 3A via step-down DC/DC converter to power the Raspberry Pi

See ./Raspberry Pi x400 Expansion Board.pdf and ./IQaudIO.pdf for details.

Changes in /boot/config.txt

Disable shitty on-board audio card:

#dtparam=audio=on

or

dtparam=audio=off

Enable x400 audio-card:

dtoverlay=iqaudio-dacplus

Reboot