Dave Plummer's M5StickC Audio Spectrum Analyzer Runs at a Smooth 30 Frames Per Second
Simple yet colorful project makes full use of the ESP32's processing power, that bright display, and the on-board microphone.
Former Microsoft programmer and father of the Windows Task Manager Dave Plummer has been looking into embedded projects of late, turning the M5StickC into a colorful live-view audio spectrum analyzer — running at 30 frames a second.
"Since the M5 contains a mic, OLED display, and sufficient computing power to both computer the FFT [Fast Fourier Transform] 40 times a second and draw the display at 30," Plummer writes of his project, "it makes for a compelling little visualizer!"
The project is simple enough: The microphone is used as an audio input, with an algorithm running a fast Fourier transform to plot the signal as a bar graph showing volume and frequency — updated live at 30 frames per second, though calculated 40 times a second.
Plummer hasn't yet shared the source code for the project, which requires no additional hardware beyond the M5StickC itself, but he's not the first to have turned a microphone and a microcontroller into a simple spectrum analyzer. Earlier this year Hackster. user Ernst Sikora shared an M5StickC-powered analyzer which drove an external RGB LED strip, while Robin Scheibler's ESP32 FFT is used as an official example for the M5StickC.
More information on the M5StickC itself is available on the M5Stack website.