Originally intended as a part of an amateur radio AmSat, this was to be a starfield tracking camera so the satellite could determine orientation. It had a custom ARM board and was programmed in C and ARM assembly.
At the U of Arizona I was the student leader for the Cubesat Program. The Cubesat was a 10cm cube weighing 1kg. I had some input in the overall design, but my primary task was all of the onboard programming. We built four microsats in all.