Posted on September 17, 2012 at 15:45That depends on your actual requirements. What a frequency resolution you need ?
The CMSIS DSP lib has routines for up to 2048 input points, i.e. 1024 frequency bins.
The floating point implementations are probably out of scope for you, but there are q31 and q15 implementation (integer), which could do. The DSP_Lib contains a fft example project, you can use it to estimate the performance you achieve.
I did it that way with the float implementation for the F4.
If you don't want the whole spectre, but just information about a few frequencies, you should look at an implementation of the goertzel algorithm, which does exactly that.
