I fabbed a couple FreeEEG32 boards [1] recently and have half of a design for my own board put together.
This technology CANNOT effectively move a mouse around on a screen today, much less control robots. If it could, they wouldn't have to implant things in paralyzed patients' brains just for basic computer control.
I do think it's a very interesting field and there's a lot of improvements to be made. It's also extremely sensitive to noise (for best signal you can't be anywhere near mains power), any movement of facial muscles completely drowns out the brain signal, and getting electrodes prepped properly is time consuming and requires skill. And even in optimal conditions the SNR is not amazing.
I'm looking into dry, active electrodes as well as inter-electrode impedance detection to solve electrode prep, and a driven right leg circuit to help SNR. TI ADS1299 (ADC used by this and most other hobbyist EEG boards - directly targeted at EEG thus fairly expensive) has impedance detection and a DRL circuit but best I can tell neither is used by most boards [2]. I'm also interested in pogo pin electrode arrays for increasing spatial resolution.
Honestly most EEG boards seem, to me, more for show and money than anything else. No one even attempts to quantify noise levels, and they have very large margins for basically being breakout boards for ADC chips. (and $300+ for a fabric cap with passive electrodes???) And no one who says "look at all this stuff you can control with EEG!" has any projects of actually controlling anything with EEG, because it's extremely difficult. They just link to old papers where someone put together a control system slightly better than random chance.
Would love to collaborate on something here if anyone has any interesting ideas, I think hobbyist EEG could be done a whole lot better.
We're not hobbyist level, I'm the co-founder of https://affectablesleep.com, so consumer grade sleep eeg, but the main point is to increase the brain's restorative function, not just measure sleep, your watch/ring is good enough for that.
We spent a LOT of time designing our dry electrodes, which work well, but in our final hardware, we've still decided to go with active electrodes (amplified signal, for those not familiar). You definitely need an RLD as well.
The ability to move a mouse with just occipital electrodes and ref and rld has been done quite a bit, and there are projects such as this (https://openelectronicslab.github.io/eeg-mouse/) which show how it's done, as well as many published research papers.
However, that isn't to suggest it's easy. As you've said, movement noise is a significant challenge. You'll need to be very still or else the electrode movement just causes a ton of noise.
Your noise level comes less from the board than the electrode set-up.
You mention [2] that does impedance measurement as well, but no link, can you post that?
I am looking at the readme on the github link, but is it not clear what the project does. Any chance you could add a bit more detail to help someone looking at the repo for the very first time?
This technology CANNOT effectively move a mouse around on a screen today, much less control robots. If it could, they wouldn't have to implant things in paralyzed patients' brains just for basic computer control.
I do think it's a very interesting field and there's a lot of improvements to be made. It's also extremely sensitive to noise (for best signal you can't be anywhere near mains power), any movement of facial muscles completely drowns out the brain signal, and getting electrodes prepped properly is time consuming and requires skill. And even in optimal conditions the SNR is not amazing.
I'm looking into dry, active electrodes as well as inter-electrode impedance detection to solve electrode prep, and a driven right leg circuit to help SNR. TI ADS1299 (ADC used by this and most other hobbyist EEG boards - directly targeted at EEG thus fairly expensive) has impedance detection and a DRL circuit but best I can tell neither is used by most boards [2]. I'm also interested in pogo pin electrode arrays for increasing spatial resolution.
Honestly most EEG boards seem, to me, more for show and money than anything else. No one even attempts to quantify noise levels, and they have very large margins for basically being breakout boards for ADC chips. (and $300+ for a fabric cap with passive electrodes???) And no one who says "look at all this stuff you can control with EEG!" has any projects of actually controlling anything with EEG, because it's extremely difficult. They just link to old papers where someone put together a control system slightly better than random chance.
Would love to collaborate on something here if anyone has any interesting ideas, I think hobbyist EEG could be done a whole lot better.
[1] https://github.com/neuroidss/FreeEEG32-beta
[2] This one does implement impedance measurement which is nice.