[sdiy] dsPIC with on-chip audio DACs

[Eric Brombaugh]

jbv wrote:
> Just curious : any chance to run realtime FFT / iFFT on these toys ?

Absolutely! The dsPIC family has built-in support for FFT bit-reverse 
addressing, and Microchip supplies source code and libraries for FFTs. 
How large a transform you can actually achieve in real time  will depend 
on what else you're trying to do however. My current project is running 
the system at near maximum CPU and DAC rates (40MIPS, 100kHz) and even a 
fairly simple NCO takes about 15-20% of the processor bandwidth.

Note also that someone on the Microchip user forums has ported the 
open-source MAD MP3 decoder to the dsPIC33 family. In a fully C-based 
implementation it can't handle stereo/128kbps, but it does work at lower 
rates & channels!

Eric