Matt Warnock said:
I'm looking for a microcontroller that can sample audio and do a FFT for
freq 400hz->4khz. I need the fund freq and the amplitude. What is a good
processor to look at?
You say you need an FFT... and then you say that you need fundamental
frequency and amplitude. Those requirements aren't necessarily
contradictory, BUT keep in mind that a FFT of 100000 points is in
itself 100000 numbers (actually 200000 with phase information), and
picking the two quantities out of the FFT isn't necessarily easier
than picking them out of the time series.
If all you really need is the fundamental frequency and amplitude, and
the "fundamental" is clean and dominant, a frequency counter and a
lock-in amplifier will get you there far more elegantly. Doing those
functions in a low-end microcontroller is very feasible.
Tim.