yeah i got it to work fine (only for sines) and even if you cant make a full tuner app, you could always release the oscilloscope as a separate project! thats reason enough for me to keep it.

also i used an old keyboard (not qwerty) that can output sine and i found that it was very accurate D3 and higher, even more precise in the upper range. keep up the good work, id love to see a real functional tuner i can have on my DS, it might help me tune timpani.