Ok, you can call me a nerd, that’s ok! Last year I bought a Lego Mindstorms robot set and when I realised that Teenage Engineering is having extra knobs which you can attach to your OP-1 and integrate it with Lego Technics parts I just had to buy those.
You can program the EV3 “brick” with easy graphical tools with your pc and send that program wirelessly (bluetooth or wifi).
OP-1 is having a funny little sequencer with which you can draw lines with knobs. I programmed EV3 to turn these knobs automatically, drawing a random sawtooth like figures.
Automatic noise machine! Perhaps I will enhance the program in the future so that you could do something more advanced with it. For example drawing random drum machine patterns would be fun.
Useful? Not so much. Fun? Definitely!