How to use the audio interface

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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