possible to connect multiple devices to one computer with a USB hub?
andrewtang
New York, USA
If I wanted to use one computer to monitor multiple devices (say 10), would it work if I connect multiple USB dongles to a USB hub, all the devices paired with the dongles would stream data to the same computer? Has anybody tried this? and what would be the (approximate) maximum number of devices that a computer would be able to monitor at once? Thanks
Comments
Andrew, hi.
Are you referring to Cyton or Ganglion. On Cyton, the GUI can be used to set the radio channel (microwave frequency) used for each individual pair of Cyton-dongle's configured. This should allow simultaneous operation. Assuming you used a library such as Brainflow. The OpenBCI_GUI just speaks to one device at a time.
https://brainflow.readthedocs.io/en/stable/
I recall there are around 20 channels available.
On Ganglion, this is using normal Bluetooth frequency band, and frequency hopping. So as the number of units goes up, more interference 'might' occur. But I believe if you use the Google Advanced Search button in upper right column, that there were some past posts by users with simultaneous Ganglions working in the same room.
Do note that the samples received by such setups are NOT synchronized in terms of sample times. So you cannot build up a 32 or more channel EEG by combining Cytons.
Regards, William
Hi William, thanks for your quick response. I am trying to facilitate an EEG experiment that involves monitoring 10 people simultaneously in the same room. I recently purchased a ganglion eval kit and am willing to purchase whatever that is needed to facilitate this experiment. I am expecting to develop my own software to collect and process the data. 4 channels for each participant would be sufficient.
Would Wifi be a better option? or what would be a viable configuration for this experiment?
re: wifi vs Bluetooth. Wifi does have more bandwidth and capability to carry more information channels. On the other hand the Wifi Shield setup is more complex than Bluetooth, and if you look at the Shop page, the Shield does not even seem to be listed at the moment. Possibly out of stock?
https://shop.openbci.com/collections/frontpage
https://docs.openbci.com/docs/01GettingStarted/01-Boards/WiFiGS
Some number of past Shield owners have found it challenging to configure and setup. And when the Shop page was active, it stated as such.
How many channels are you using per person in the same room?
4 channels per person is sufficient for this experiment.
The reason I ask, is that in the past, a number of OpenBCI users have used Cyton 8 or 16 channel units to connect a single channel to each person in the same room. So conceptually could support 16 single channel connections to individuals. One consideration however is that the more and longer the electrodes are, the higher the noise factor.
http://eeghacker.blogspot.com/2015/03/brain-controlled-shark-attack.html