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
Audio will play through the headphone jack at max volume, just plug in your favorite headphones! (Warning: it may be really loud!)
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
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)
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.
If you want to change the volume of the headphones, you'll need to run the audio mixer software amixer
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