A Four-Arduino Spectrum Analyzer
This device uses four individual Arduino Uno boards and LoL Shields to display sound in 36 different bands.
When you want to visualize music, a spectrum analyzer is a great way to do so, showing how a sound’s volume is broken out between different frequency ranges. While many would consider making one with a microcontroller and addressable LEDs, "tuenhidiy" decided to do things a little differently. This project instead uses four Arduino Uno boards with their own LoL Shields to display sound in 36 different bands.
The device takes in sound info from a stereo jack, passing it along to each Arduino board in parallel. The Arduinos then process the sound using fast Fourier transforms, effectively dividing the sound between left and right channels, as well as a lower and upper frequency range on four distinct sound panels. It’s an interesting take on “parallel” processing, and the modular nature would certainly open up various possibilities for modification.
The analyzer utilizes 126 LEDs per shield for a total of 504 individual lights, and different colors and styles are chosen for each panel. Power is provided by a portable USB bank, and the assembly is stacked together on an acrylic frame. Be sure to check out the device on display in the video below, and PCB info for the Charlieplexing LED shield is found on GitHub.