RFFT in CMSIS DSP. Part 1.
RFFT in CMSIS DSP. Part 1. RFFT in STM32 using CMSIS DSP. Part 1. Python warm-up for illustration I always wanted to use MCU for audio processing. And for my purposes, I need Discrete Fourier Transform(DFT), especially its fast version FFT. If you do not know what is this, read Wikipedia first:) FFT has a huge number examples of usage, for my case I want to build wavetable synthesizer. Let’s take some real example. We have an audio signal, which is just a set of amplitudes, which you will take from your ADC. Samples are taken with some sampling frequency Fs. For preliminary illustration, we’ll use Python. import numpy as np import matplotlib . pyplot as plt # Our wave settings N_samples = 32 amplitude = 10 # Here we'll generate our sine wave t = np . arange ( N_samples ) x = amplitude * np . sin ( 2 * np . pi * t / N_samples ) # Plotting fig , ax = plt . subplots ( ) ax . plot ( t , x , 'bo-' ) ax . set_xlabel ( 'N sa...