A Korg Mini Pops Clone rhythm machine, based on the work by Jan Ost and his O2 synth. I was inspired by his O2 rhythm machine code for the Arduino, and decided to design a PCB for it.
The MiniPops / O2 rhythm machine is quite simple. You have one potentiometer to select the rhythm pattern you want, (out of 16 available) 8 switches to select the tracks of the rhythm you want to play, and another potentiometer to select the tempo.