Nicolas Electronics

Electronic projects and programming


Optimizing the Fast Fourier Transformation

The idea of writing a Fast Fourier Transformation came to me when we had to chose a project for my embedded system class.
At that time, we were given the Stellaris LM3S6965 Ethernet Evaluation Kit to work with.

I’d just learned about the Fourier transformations and I really wanted to try and code a Fast Fourier Transformation. So why not try this on the Stellaris board ?

This board has a 128×64 OLED display which is excellent for me to display the amplitudes of the Fourier transformation.


Inverse Fourier Transform from a Forward Fourier Transform

I was given the idea to make an equalizer, or to at least try making one.
The way you make an equalizer is by taking some audio samples, use the FFT transformation on those samples then modify the amplitude of the FFT output at the desired frequencies and use those modified amplitudes as an input for an inverse FFT.
The output of the inverse FFT will give you a new set of samples that you can use and send to a DAC or other digital to analog converter.