You can generate an FFT (fast-Fourier-transform) plot by periodically collecting a large number of conversion samples from the output of an ADC.

This example processes framebuffer data from the Mozilla Audio Data API MozAudioAvailable event. The Fast Fourier Transform algorithm is used to obtain audio frequency levels which are then ...

That’s the idea behind the Goertzel. It is essentially a fast Fourier transform algorithm stripped down to compute just one frequency band of interest.

Realizing that his Fast Fourier transform (FFT) code was eating up too much processor power, it seemed like a great time for him to explore using the ESP32’s second core.

Although examples have been given showing that the spherical average of the Fourier transform cannot decay always too fast, they usually do not exhibit a single measure decaying sufficiently slow on ...