Thomas McDonald's "Ohsillyscope" Provides Live Audio Visualization From a Raspberry Pi
Built atop a Raspberry Pi 4 and an Adafruit RGB Matrix HAT, the Ohsillyscope snags live audio via ALSA and turns it into a waveform.
DevOps engineer and computer science major Thomas McDonald has designed a Raspberry Pi-powered audio oscilloscope to liven up musical performances — and has released the source code to his "Ohsillyscope" under an open source license.
"Last time I posted this I got a lot of interest and people asking for the code," McDonald explains of the reason for the project's release, "so I finally got around to making the code open source. It's [based on] a 64×64 matrix. The plan is to hook it up to our band's setup and have live visuals."
Amusingly dubbed the "Ohsillyscope," McDonald's audio visualizer uses a 64×64 RGB LED matrix panel connected to an Adafruit RGB Matrix Hardware Attached on Top (HAT) add-on for a Raspberry Pi single-board computer. Designed for real-time audio capture, the project reads from Advanced Linux Sound Architecture (ALSA) sources and creates a live waveform image for display on the matrix.
"It’s writing the sound card buffer directly to a pixel," McDonald explains of the software's operation. "[I've now] made it completely portable, [and] it's gonna make gigging super fun. If you wanna make this repo better please submit a PR and I'll gladly let people collaborate!"
The project's source code has been published to GitHub under the reciprocal GNU General Public License 3.0, though McDonald apologizes for how vague the corresponding documentation is. "I made this project months ago," he explains, "and forgot all the initial setup I had to do."
More information is available on McDonald's Reddit post.