[goodbyegti]

It's mind blowingly expensive. A very quick breakdown of the main parts:

ADS1299 ~38USD for 1k+

ATMEGA328P ~ 2USD for 2k+

RFDuino ~ 20USD for 10 +

Accelerometer ~ 2USD for 1k+

Board ~ 5USD assembled for 1k+

I'm also not sure I'd want to have an RF module near a 24 bit ADC.

Total is probably around 75USD for 2k+. Simple layout as well.

[ErikRogneby]

Thank you! For a open source hardware project I was looking for the BOM(and wondering at it's real price). Presumably there is some R&D recoup baked in to this price, but when other micro controllers and kits sell for ~$25-40 to see this over a factor of 10 more expensive was surprising.

[fundamental]

I was looking at mouser when you posted this and was getting fairly similar numbers (though not quite as low). The price certainly does seem high.

What sort of markup would you normally expect for relatively simple electronic projects like this?

[goodbyegti]

If it's been done nicely 100% would seem fair to me for a low volume project like this. That's only my opinion however.

[bayesianhorse]

Thank you for the opinion. The price is the main reason I don't see myself buying one in the near future.

I rationalized the price because I figured it is very hard to build a nicely running prototype board with the (specialized) amplifier chip, and that there was at least a 100 or 200$ pure "convenience" charge in it.

[goodbyegti]

For an EE it's pretty easy to put these parts together and make them 'work', but it's fair to say that making the most out of a 24bit ADC is no easy task. That is unless you want 8+bits of noise on the line. You need to take great care decoupling the digital side from the analogue side, and also with the routing of the ADC inputs - guarding / shielding etc. If that's all been done properly it would certainly be worth paying a premium for the time that's gone into the design. I guess the question is has it?

[bayesianhorse]

I don't know if it is. But I also don't believe most people interested in BCI or biofeedback are electrical engineers...

[etrautmann]

My entire lab is filled with EE's focusing in neuroscience and brain-machine interfaces. We use implantable electrodes though, much better SNR and fewer corrupting noise sources.

[csbrooks]

Noob question: When you say "implantable electrodes", you mean for humans, or for animals?

[bayesianhorse]

Usually humans. I'm not involved in this kind of research, but BCI with implanted electrodes probably refers to cases where these electrodes are implanted for some other reason.

For example it can be necessary to find an epileptic seizure hot spot because you can't stick someone in an MRI tube for a few days on end.

It's hard to actually make a case for BCI as an assistive technology, because every single sceletal muscle in your body provides a better input signal than EEG ever could, and there aren't so many cases where people don't have any voluntary muscle function left. (My opinion... need not be correct!)