For this assignment, I set out to create a two-voice synth/sequencer. A major goal of mine was to be able to create each of the basic waveforms (I ended up with sine, square, triangle, and noise), so I made two R2R ladder DACs, each with a controlling arduino pro mini. The two pro minis were then controlled by an uno that told them what waveform to use, and what note to play. The uno had arrays of notes that it would tell each pro mini to play, and I threw together an interface for inputting them.
I’ve essentially learned that analog circuitry is really hard, especially on breadboards. I tried to do more thorough unit testing as I went on, trying different values for filters and making sure that I was getting the correct waveforms at the correct frequencies, but when all put together, it just kinda shat the bed. There were likely issues in the final signal combining and amplification, but then again, there were likely issues in every step. I think that in the future I’ll try and step away from using as much electronics and do something more material. I think this kind of project could have turned out well if I was able to put more time into it, but sadly I need to graduate.
At the very least, the sounds it makes are kinda spooky so it’s fitting for Halloween.