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Raspberry Pi Test
Speaker Tests!
OK you can use whatever software you like to play audio but if you'd like to test the speaker output, here's some quick
commands that will let you verify your amp and speaker are working as they should!
Simple white noise speaker test
Run
speaker-test -c2
to generate white noise out of the speaker, alternating left and right.
If you have a mono output amplifier, the I2S amp merges left and right channels, so you'll hear continuous white noise
Simple WAV speaker test
Once you've got something coming out, try to play an audio file with speaker-test (for WAV files, not MP3)
speaker-test -c2 --test=wav -w /usr/share/sounds/alsa/Front_Center.wav
You'll hear audio coming from left and right alternating speakers
Simple MP3 speaker test
If you want to play a stream of music, you can try
sudo apt-get install -y mpg123
mpg123 http://ice1.somafm.com/u80s-128-mp3
If you want to play MP3's on command, check out this tutorial which covers how to set that up (https://adafru.it/aTD)
At this time, Jessie Raspbery Pi kernel does not support mono audio out of the I2S interface, you can only play stereo,
so any mono audio files may need conversion to stereo!
Volume adjustment
Many programs like PyGame and Sonic Pi have volume control within the application. For other programs you can set
the volume using the command line tool called alsamixer. Just type alsamixer in and then use the up/down arrows to
set the volume. Press Escape once its set
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