Week 06 : embedded programming
Hi Teo, Nice week (as usually), and cool first tests.
Python test would be great :-), it is pretty straightforward to get with Thonny! (https://thonny.org) or even simpler with circuitPython.
My two cents : for me what you do is not exactly an "octave" change, as you multiply by 1,2,3 (octaves musically speaking are power of two, so should be 1,2,4 if you use in a multiplication) => actually the most efficient way to do it would probably be to keep those 1,2,3 and use it to left-shift your values by doing something like int frequency = notes[noteIndex] << (octave-1);
that will actually multiply your frequency by 2^(octave-1) (so 1,2,4 for 1,2,3 octave-value). Shifting is a very natural operation for micro-controllers. (1-cycle instruction)