USB Audio

Using Raspberrylink with a USB Sound card

If you're not using the pi's onboard sound, and instead using a usb device, we'll need to change some configuration options.

First we must ensure the USB sound card is being used as default, which can be seen with a guide here., and then rebooting.

NOTICE: Recently the above hasn't been working, so a workaround is to straight-up disable the on-board audio to force the USB device as the default audio. You can do this by creating a file /etc/modprobe.d/alsa-blacklist.conf with the contents of blacklist snd_bcm2835 and rebooting. This disables the loading of the Pi's audio driver, leaving our USB one as the only device available.

Telling RaspberryLink about our USB device

Now we can change our options. First we need to figure out the IDs for the microphone and output (or just output). Run amixer controls. You'll see some output. We want to look for the line that looks somewhat like this:

numid=6,iface=MIXER,name='Speaker Playback Volume'

and also the line

numid=8,iface=MIXER,name='Mic Capture Volume'

The "numid" might be different, but we need that number. Write those two down and then open /etc/raspberrylink-server.conf

Set the line mixer-numid-output= to the "numid" from "Speaker Playback Volume", and then mixer-numid-input= to the "numid" from "Mic Capture Volume".

Reboot, and you should have working USB audio for raspberrylink!