FM Synthesizer

This is a little, 1 octave FM synthesizer made with an Arduino Nano. I didn't code it, it was created by Rolf Oldeman. However, I modified the code and added buttons for changing the octave it plays in. Then it can play a wider range of notes while being very small. It was a challenge to figure how everything worked. The original code is in Arduino C, which is quite a "low level" language, often communicating directly with the hardware for speed.