Oyu released the source files for its wearable EEG device, including designs for three boards, firmware, and signal validation
Oyu released the source files for its wearable EEG device, including designs for three boards, firmware, and signal validation
On 3–4 August, the creator of the Oyu project released the source files for a wearable electroencephalograph under the MIT license. The release includes schematics and fabrication archives for three boards, a bill of materials, firmware, and photographs of the assembled prototype. The repository also contains one test performed on the head. When the participant closed their eyes, an alpha peak appeared near 10 Hz on the OUT0 channel, and the power in this frequency range was 29,66 times higher than with their eyes open.
An electroencephalograph records the difference between the very weak voltages measured by electrodes placed near the head. The Oyu repository documents the entire signal path. An AD8422 instrumentation amplifier amplifies the voltage difference, a 24-bit ADS1220 ADC converts the signal into numerical values, and an ESP32-S3 sends the samples to a computer over USB. The firmware transmits raw digital samples in CSV or JSON format and switches the ADC inputs.
A graph shows only the final signal. The schematic, bill of materials, and software make it possible to trace the chain backward. They show where each electrode connects, which components the signal passes through, and which samples are written to the file. The fabrication guide contains Gerber archives (the files used to order printed circuit boards), schematic diagrams, the pinout, and assembly photographs. This documentation turns the device into a design that others can inspect and reproduce.
The creator tested the assembled signal chain by recording with the participant’s eyes open and closed. The alpha rhythm consists of oscillations in the brain’s electrical activity, typically within the 8–12 Hz range. Oyu shows a peak near 10 Hz on OUT0 and higher power when the participant’s eyes are closed. This test connects the electrodes, analog circuitry, digitization, and recording process to a single observable result.
Another developer can assemble the same board, replace an electrode or modify part of the analog circuit, record a new file, and compare the signal. The entire procedure can be reproduced, not just the concept behind the device.