larger number of channels ?
I'm interested in a 32 channel configuration EEG.
The openbci boards be capable of being put together this way.
For 16 Channel,I find the following code in the processing.
//use this for when daisy-chaining two OpenBCI boards
//int openBCI_baud = 2*115200; //baud rate from the Arduino
//final int OpenBCI_Nchannels = 16; //daisy chain has 16 channels
For 32 Channel, the following code is OK?
//int openBCI_baud = 4*115200; //baud rate from the Arduino
//final int OpenBCI_Nchannels = 32; //daisy chain has 32 channels
Comments
The openbci stuff is really exciting! Great work!
I'm personally interested in a 32 channel configuration eeg.
Can you indicate what would need to be done to achieve this?
In other words, will the openbci boards be capable of being put together this way, out of the box so to speak? Would there need to be software and/or hardware changes? Any testing already been done?
Out of curiosity are the boards currently utilising standard or daisy chain mode (acc. ads1299 datasheet)? How many openbci boards can be combined (particularly considering the bluetooth connection)?
Good luck (and God speed!) with going live...
Generally, what would be the process for adding one more
daisy module for a total of 24 channels? I would envision buffering the output
through the SD card to conserve bandwidth on the wireless link, but I am not
sure how to proceed with the hardware modification.
Also see this other thread on how to possibly setup wifi output as an alternative to bluetooth. The wifi link may be fast enough. That goes for @Sifeng as well.
http://openbci.com/forum/index.php?p=/discussion/243/hard-wire-transfer-eeg-data-to-external-device
William
I am a new to OpenBCI, and planning to buy the 16-channel
biosensing board. I was wondering if it is possible to have more than
16 EEG channels using OpenBCI? Has anybody tried, or have any idea of
using, may be two OpenBCI kits at a time.
I am planning to acquire signals using Python or MATLAB.
Thanks.
I am a neurologist and I am making a software can help patients with neurodegenerative diseases to draw. I need a low-budget 32/64-channel EEG. I have no experience in remodeling electronic equipment. Where can I buy a modified 32/64-channel OpenBCI EEG?
Mikhael, hi. The 2015 quote from Joel Murphy is very old. Sorry for any confusion. No OpenBCI products are capable of 32 or 64 channels, even with "external trigger" idea. The master clock must be aligned exactly for all ADS1299 chips.
Such an expandable product IS on the TODO list.
Regards, William
Very old thread, but I could not get any newer information. To have more than 16 channels would be great, the the “external trigger” idea is also great. What about streaming multiple OpenBCI boards into one Infux Database?
To measure coherence, synchrony, phase, etc, all channels must sample at exactly the same time.
Thank you, William. Is there a computer scientist who wants to stream two OpenBCI boards into an InfluxDB, synchronize the boards by an external trigger, and write a paper about it? It could be to be revolutionary for the world of EEG devices.
No. The 'external trigger' approach will STILL not work. ALL CHANNELS need to sample at exactly the same moment in time. Otherwise many metrics such as phase, coherence, P300 sample averaging, etc., are meaningless.
So you don t see a solution to join the sensor data from different OpenBCI boards in a single Influx Database, William?
No, it is impossible, as I've said several times, with the current Cyton hardware. Investigate some other EEG amps that provide 19, 24 or 32 channels. ALL the channels must sample at the same moment in time. Otherwise many metrics such as phase, coherence, P300 sample averaging, etc., are meaningless.
The OpenBCI staff is currently devoting all engineering efforts towards the Galea headset. It's remotely possible that another product may surface in the future with more channels. But I have not heard of it, though I have lobbied for such.
Thank you William for your answer.
"No, it is impossible, as I've said several times, with the current Cyton hardware".
You mean a hardware change could solve the problem?
"Investigate some other EEG amps that provide 19, 24 or 32 channels."
I did this already, I don t know if it worth it to spend the extra costs. I am a Physiologist working on a private project an I am interested in Gamma waves in the left prefrontal cortex. I did not test yet wether 32 channels are necessary for this purose. But I thinks the time is there for a low cost high quality 32 channel device. I have evaluated several devices with the potential of 32 channels with a good cost to power ratio. But the problem of some of these devices seems to be the software. And I could not find any papers which use these devices regularly and on the long term.
"ALL the channels must sample at the same moment in time. Otherwise many metrics such as phase, coherence, P300 sample averaging, etc., are meaningless."
Are all of these metrics necessary for all applications? Aren t there applications which can to without some of these metrics?
"The OpenBCI staff is currently devoting all engineering efforts towards the Galea headset. It's remotely possible that another product may surface in the future with more channels. But I have not heard of it, though I have lobbied for such".
OpenBCI currently not devoting engineering efforts in more channels. You say it is possible that another product may surface in the future with more channels. This would be great. I will lobby for an OpenBCI product wich more channels either, since the OpenBCI standard has a good acceptance in the scientific community.