I’ve always been fascinated by brain-computer interfaces and the idea of making brain activity visible. What started as a “what if I could build this myself?” turned into a full custom EEG (Electroencephalogram) device — from PCB design to digital signal processing on an STM32 microcontroller.
The goal: create a single-channel EEG that is low-cost, reproducible, and sensitive enough to detect the brain’s transition into a relaxed “eyes closed” state by picking up alpha waves. And share my process with other builders so they can replicate it as well!
My Views on Building an EEGThis project started as a personal challenge: could I really design a medical-adjacent device, from PCB to DSP, on my own? If I really could achieve such a feat I would set it as my flagship project on my portfolio that thought alone made it very exciting. At first I underestimated how tricky EEG signals are — the noise, the grounding, the sensitivity of electrodes. At around 60 hours of making the project the excitement ran out but i had too much work put in already to give up. Debugging the analog front-end was the hardest part. Nothing worked for like 4 to 5 days i had to sit in my makeshift lab i put together for 750 dollars. The breakthrough came when I finally saw a clear alpha wave jump with eyes closed — that moment made the ~150 hours of work frickin worth it. What surprised me most was how even a single channel can capture such meaningful brain activity. It allowed me to appreciate the engineers on Neurotech I built a single channel without full ICA (a DSP algorithm that makes the EEG signals cleaner). But there are engineers are out there building much more complex devices and kudos to them they won my heart when i realized how hard really is to getting a signal from the human brain really is. If you guys are curious i can make a list of my lab equipment / photos of it. What did i use etc. Much love.
Open SourceAll files are available — PCB Gerbers, BOM, firmware, and a 35-page report explaining the design process. Feel free to build your own, test it, or even improve it!
📂 GitHub repo:Custom 1-Channel EEG▶️ Demo video:YouTube
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