stream from two Cyton's at once, how to change channels? [resolved]
Hello. I am trying to stream two Cyton boards at the same time. However, I am facing some interference issues where there is a cross talk with the two dongles of the Cyton board. I read in one of the forums that I need to change the channel but didn’t give any reference on how to do that. Have anyone tried this before? If so, can they advise me on how to make the channel change?
Comments
Expand section 5,
https://docs.openbci.com/GettingStarted/Boards/CytonGS/#5-optional-settings
Turn off both boards and remove dongles. With the 1st Cyton and dongle, turn them on and use the Get Channel to note their current channel number. Use adhesive tape labels to put this number on Cyton and Dongle. Now turn off/unplug, this pair.
Turn on 2nd Cyton and dongle. Get Channel will probably show same channel number. Use Change Channel to pick another number; label both with new number.
William
Thanks for clarifying @wjcroft!
Also, you could try separate the dongles with some space for better results (as confirmed by another user operating two Cytons). This can be done with a short USB extension cable or a powered USB hub.
Would you happen to be the same individual who asked about this on BrainFlow slack? @msl052
Hey @retiutut. No I wasn’t the one who asked about the BrainFlow. Thank you for the advice!
Hi,
I'm recording EEG of two people at the same room by using two Cyton-Daisy board systems.
(each system is connected to each labtop)
My problem is..
When i started recording from one Cyton-Daisy board system, then the other system doesn't work...
I searched the problem and i found that it is possible to select channel (Radio Configuration) at OpenBCI GUI.
I tried this and it worked.
But unfortunately, I'm using the Python (brainflow) for control recording... Not OpenBCI GUI..
Is there any way to select channel by using the Python?
Or, I need to find other ways to do it unless using Python.
Thanks.
@JaehyungKwon, hi.
I merged your question into this existing thread. Please read previous comments. You change channels using the GUI, then you can continue with Python / Brainflow access.
William
Thanks.
After i changed channels using the GUI, the channels seems to be maintained as i selected.
I'm running a lab course with 9 Cyton boards running in a large room together. I'm running into similar problems. I tried steps like this in the lab today, but didn't quite get to a good state. I have some questions about the above suggestions:
1 - If I get a dongle+Cyton set for a certain channel number, that persists across power cycling? Does it persist across pressing the reset button on the Cyton board?
2 - After a channel has been chosen that works for a dongle+board, can the user just use the "start session" option for future runs, or must they go and use the manual mode each time to make sure the auto-select of channel doesn't happen.
3 - Is there a benefit to spacing the channel numbers? My first inclination was to have the 9 groups use channel numbers 1-9. But would it be better, interference-wise, to use 1/3/5/7/9/11/13/15/17?
4 - My plan, based on the help provided in other posts in this thread, is to have the users start up their systems one at a time, select a channel, write it down, and then close down the system. That way only one cyton board is active at a time in the beginning. Is that the right procedure?
Thanks for the help!
Matt, hi.
Channel selection is persistant, yes, through all power cycles or resets. You definitely want to only power up one Cyton / Dongle pair at a time, until you have set the desired channels. Then power up order is irrelevant. Can even be simultaneous. Continue reading.
Channel selected stays selected.
Probably there is a bit more isolation with wider separation. So you even might be able to go: 1 / 4 / 7 / ... Etc. But try your spacing above first.
That should not be necessary, as the channel stays selected. Once all the channels are set, power up sequencing is irrelevant.
One other tip mentioned on other threads when there is Bluetooth interference, is to use a usb extension cable to place each dongle closer to the respective Cyton. That increases the signal strength.
William
Thanks!