PIC32MX: Inverse FFT

Overview

An inverse FFT is a function that converts a frequency domain signal into a time domain signal. Inverse FFTs actually use the same algorithm as FFTs except with some scaling and conjugation or time reversal (depending on the algorithm). FFT information can be found at PIC32MX: FFT of Analog Input. The following circuit and code implements a program on the PIC32 that creates an analog signal, takes the FFT of that signal, and then takes the inverse FFT of the result to try and obtain the original waveform back. The data is all sent to MATLAB via RS232 and compared to MATLAB's computational results for accuracy.

The code for both MATLAB and the PIC32 can be found at the bottom of the page or downloaded here.