Hello, this is my latest project, it's the Yun as an aux music player, and the tunes can be selected by the client connected to the yun's web server. In this example I chosed some Nintendo tunes but any mp3 tune will work too.
The front-end was made on html+css (no javascript needed), and the back-end on python's flask.
No code was done on the atmega32U4, everything is in the linux side of the yun.
To reproduce mp3 tunes I use a usb soundcard and installed madplay.
I can share the code if someone is interested.