Audio

Playing Local MP3s

You can play MP3's off of your USB key or if you've copied any to the /mnt/storage space with btplay –start-daemon file.mp3
MP3's will play in the background. To kill btplay run killall btplay

Audio will play through the headphone jack at max volume, just plug in your favorite headphones! (Warning: it may be really loud!)

Playing Remote MP3s

You can also stream music with btplay, just stick a URL in there! Of course, you will have to have network capability up and running first
Just as before, just plug into the headphone jack to verify its working. (Warning: it may be really loud!)

Splitting out the A/V

The headphone jack is not actually just audio - its actually Audio and Video. That means that you if you just plug headphones you'll notice some buzzing - thats you listening to the video! Now if you're in a Cronenberg film this is probably OK but for most of us its very annoying! There are two solutions. One is to split out the 3 signals into RCA jacks (with a camcorder cable)
and then recombining with an RCA Y cable (such as a Y female-RCA to male 3.5mm or this

Note our A/V cables split out the signals as such - Red is Video, White and Yellow are stereo line-level audio which is not what you would expect!

Note apparently like every A/V cable is slightly different. If you get one, try different colors to figure out which ones have audio coming out of them and which have video.

Using the Mixer

If you want to change the volume of the headphones, you'll need to run the audio mixer software amixer
You can get and change the HeadPhone volume (HP) by running amixer sget HP and amixer sset HP
To set the volume to 1/2 for example, do this amixer sset HP 64

Speaker

The iMX.233 has a built-in mono speaker amplifier that can push up to 2W into a 4 ohm speaker! To use, connect the two speaker inputs into the Spkr 0.1" JST connection near the power jack. You can use either pin, they are not polarized as it is a mono output. Don't ground either of the speaker pins, they are "bridge tied" to improve output volume

The chumby is 'switched' by default - if you connect headphones into the jack, the speaker will turn off and vice versa.

If you want the speaker on even with the headphone plugged in, you can use amixer cset
For example, the Speaker Playback Switch is off, so we turn it on with amixer cset numid=4 on to reactivate
This guide was first published on Dec 12, 2012. It was last updated on Dec 12, 2012. This page (Audio) was last updated on Jul 27, 2019.