FFT

ApproxFFT

ApproxFFT: Fastest FFT Function for Arduino | Arduino Project Hub

EasyFFT

EasyFFT: Fast Fourier Transform (FFT) for Arduino | Arduino Project Hub

EasyFFT: Fast Fourier Transform (FFT) for Arduino : 6 Steps - Instructables

8-64 Channel FFT Spectrum Analyzer : 6 Steps - Instructables

Code

GitHub - donnersm/FFT_ESP32_Analyzer: Spectrum analyzer 8-64channels FFT

GitHub - fakufaku/esp32-fft: Vanilla single-precision radix-2 FFT for the ESP32.

GitHub - s-marley/ESP32_FFT_VU: A spectrum analyzer VU meter for the ESP32 and a FastLED matrix