Fast4ier

An FFT and IFFT Arduino library.

Note: You may need a board with a lot of RAM sometimes. I currently recommend the teensy 4.x for its speed and large amount of RAM (it's very fast with a default of 600MHZ and a max built-in overclock of 1.024GHZ with cooling/heatsink).

inclusion

#include <complex.h>
#include <fast4ier.h>

Usage

Enabling Double precision instead of float

The default of float may help reduce RAM on some boards. However, some do not differenciate between float and double precision (they are treated equal).

#define FAST4_DOUBLE

Defining arrays

complex mySamples[bins];

FFT

Fast4::FFT(complex input[], complex output[], int bins);

in-place:

Fast4::FFT(complex data[], int bins);

IFFT

IFFT is useful for creating sfx.

Fast4::IFFT(complex input[], complex output[], int bins);

in-place:

Fast4::IFFT(complex data[], int bins);

Polar conversion

Can be used for spectrographs.

Polar coords stored as a complex number: (Amplidude) + (Phase)i

Polar::toPolar(complex input[], complex output[], int bins);

Polar::fromPolar(complex input[], complex output[], int bins);

in-place:

Polar::toPolar(complex data[], int bins);

Polar::fromPolar(complex data[], int bins);