I wanted to use a Raspberry Pi to play some songs (mp3s) through a very simple interface. Something where you can just type in a number and a corresponding mp3 file would play. This is what I've come up with:
The songs play with mpg321, a simple and lightweight mp3 player. I've used a spare "Dream Cheeky" LED display to show which mp3 is being played (by number). Obviously in the photo shown above there is nothing plugged into the audio socket ... but it was easier to take the picture this way.
The LED display is driven by the excellent dcled utility which works perfectly on the Raspberry Pi. A cheap numeric keypad allows input (although I have also made a web-based interface too).
I'll probably describe some of the software in more detail, when I have time.