How to use the audio interface

How to get sound out (audio out)


The amplifiers for the headset output are disabled by default, so the first thing you'll do is enable these amplifiers with:

amixer set -D hw:0 'Headset' 0dB
amixer set -D hw:0 'HeadsetL Mixer AudioL2' on
amixer set -D hw:0 'HeadsetR Mixer AudioR2' on

Then you can easily play a *.wav sound with the application Aplay, for example:

aplay sample.wav

How to get sound in (audio in)

Enable capture:

$ amixer -c 0 sset 'Analog Right AUXR' cap
$ amixer -c 0 sset 'Analog Left AUXL' cap

You can record audio in with the application Arecord, for example:

arecord -t wav -c 2 -r 44100 -f S16_LE -v audio-in.wav

Following output is expected on console:

Recording WAVE 'audio-in.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
Plug PCM: Hardware PCM card 0 'TWL4030' device 0 subdevice 0
Its setup is:
stream       : CAPTURE
access       : RW_INTERLEAVED
format       : S16_LE
subformat    : STD
channels     : 2
rate         : 44100
exact rate   : 44100 (44100/1)
msbits       : 16
buffer_size  : 32768
period_size  : 2048
period_time  : 46439
tick_time    : 7812
tstamp_mode  : NONE
period_step  : 1
sleep_min    : 0
avail_min    : 2048
xfer_align   : 2048
start_threshold  : 1
stop_threshold   : 32768
silence_threshold: 0
silence_size : 0
boundary     : 1073741824

When ever you think you want to stop recording just press CTRL+C