Hi Speck,

It should be possible to do with hardware PWM, espescially at low frequencies like that. I just never got it working very well at higher freqs, so i never really finished it off to see where the limits were. Feel free to carry out your own investigation cause it should be possible.

I think it was probably due to the fact that the loop runs at 5000000/28=178,571kHz and the highest (useable) PWM freq was around twice that ....... no resolution. However, like i said, i never took it all the way, i got the results i wanted with the R-2R ladder.

/Ingvar