Hi,

I hope everyone is safe in this very strange situation we are dealing with.

I have been working lately on the "644/1284 Narrow" project, and also a project for a teacher who would like to show his students how to compute the speed of a bike by analyzing the sound of a probe rubbing on the side of the tire. Since the tire rubber has 2400 little grooves it creates a sound proportional to the speed. I am still working on it and having some difficulties with my old tire… I hope he will be equipped with a brand new one!

For this reason I was focused on an fast Fourier transform (FFT). This computation requires as much RAM as possible, so it constitutes a good example of a memory intensive application. Since the 1284 Narrow board has 16 KB of RAM, I tested the algorithm on it, and it is working perfectly well. From this I decided to publish this Instructables tutorial.

I hope you will be interested, and let me know if you have some comments.