How to build a 32 channel EEG headset by ourselves?

Last Updated on August 5, 2023 by pg@petergamma.org

The Epoc flex 32 heatset has the following issues:

  • the analog to digital conversion rate is only 14 bit, for research applications 16 ADC is recommended, OpenBCI Cyton modules for instance havd 24 bit ADC.
  • the Epoc flex 32 needs to be connected over usb to a computer which is risky, for 32 channels to stream over Wifi the bandwith of the Epoc flex 32 is to low.
  • LSL needs a software subscription. LSL for Python requires an x86 processor and does not run for instance on Raspberry Pis.

If we do not want to build a multi-sensor EEG device from single electronics components and InfluxDB as suggested here:

Our sugestion:

  • Connect 4 OpenBCI Cyton boards which have an issue- free with WIFI shield:

https://www.ebay.ch/itm/284876280716?hash=item4253f3138c:g:CLoAAOSwpepiu~95&amdata=enc%3AAQAIAAAA4MgG4qLvVaorVIcocrfwsuUstbiXLXRme41j0b1iPpkreQ9Vp7Nt9HFbXgUjERqwgG9mFw9J37g2g%2FTMkenpJYLYdnWwrp7nBV8GV2d%2Bv9cg8ew1sh4jfe2SY2hlStAVG36KpmKY2rroZnwK%2FAGRbX4Bt%2BRvLeSrK4GkbAHyk8sNfAHzPvo4f0qAkXbXmZOC9sJSYUNCXfaM9yf%2Bx2316E%2BVmK5OWnzlNBYJtGBnTw3bvgymfHj11uWzqkRe%2BRx5M4ik22JVYj4oElAbM9Xkfw%2F4SxsJfAZsdOYwx6NFs72a%7Ctkp%3ABk9SR4TDr5GmYg

  • or 2 OpenBCI Cyton + daisy + Wifi shield (if we find this modules with a WIFI shield which has no issues somewhere) to a database based on InfluxDB, as we suggested here:

This setup does not offer all the parameters of other EEG devices, for instance phase and coherence are missing. We have to check if we can do with those parameters as a temporary solution until we find a better solution.

To have all the parameters in InfluxDB, a hardware modification of the Cyton board is necessary, we suppose this would require an additional buffer. But this is also a solution we can think about.

  • This solution offers the option to add additional sensors to the device, as for instance ECG, PPG, MEG sensors or Apple watches.
  • Www.OpenBCI.com does not recomment connections over cable, it is hardly used, but BrainFlow has implemented cable connection:

https://brainflow.readthedocs.io/en/stable/SupportedBoards.html

  • This is a solution which we can choose if the WIFI option with OpenBCI should not work.