OpenBCI with more than 16 channels with an external clock for the ADS1299 & a data bridge (part II)?

Last Updated on September 27, 2024 by pg@petergamma.org

The OpenBCI firmware seem to work without issues with the ADS1299 chip. But not the Arduino board with the ADS1299 demo kit.

The effort too big to develop a firmware for the ads1299 to support more than 16 channels?

This makes OpenBCI still the most interesting architecture to see if we can modify it. Peter Gamma from www.petergamma.org is a hobbists as far as products from www.openbci.com. He has never used those or tested those, but has reviewed it over a longer period of time. A limitation of OpenBCI is that it only works uop to 16 channels. To use it for instance with InfluxDB, all channels on different OpenBCI Cyton modules would be needed be sampled at exaclty the same time. With the current OpenBCI architecture, this is not possible.

Others have used the ADS1299 TI demo kit with daisy chain for 32 channels. Or the Beats device with daisy chain for 32 channels. But both device have hardly any followers, and seem to have issues. But the ADS1299 can also be used with an external clock. This clock would need to be synchronized over the OpenBCI Cyton modules. But there is no direct data connection to synchronize a clock signal over the differen Cyton modules. We think it is worth discussing of such a modifcation would be possible.

Sellers on eBay and Aliexpress are very creative in modifying OpenBCI modules. But as far as we have seen, they offer only one demo product and sell it then. But eventually it is possible to solder such a bridge by ourselves. But this needs advanced knowledge about the ADS1299 chip, about the OpenBCI soft- and hardware, as well as advanced soft- and hardware skills. And we do not know if
this would be possible.

Devices based on InfluxDB do not have these limitations. But we currently do not such an EEG device based on InfluxDB. To evaluate it, to study it, to build it, takes a lot of time. The OpenBCI documentation is quiet extended now, and we do not know of such a documentation for EEG devices based on InfluxDB. And it takes time to find such information. Therefore we think it is worth having once more a look at the OpenBCI architecture and how to extend it.