Issues with failure to retain data stream and packet loss with a Cyton+Daisy system
I have been working on a system for the collection of EEG data from participants during mental imagery tasks. I am using a Cyton+Daisy system for recording the EEG data. I have been using an LSL to record all of the EEG data along with time markers sent to the LSL by the image presentation software, PsychoPy, indicating which stage of the trial participants had completed during data recording. I am using the open-source LabRecorder software for implementation of the LSL.
This system worked well last semester, however it has recently developed issues with the Cyton system becoming disconnected/failing to reconnect with the computer. Usually, during recording, a message would appear on the screen saying “An error has occurred during data recording, close the GUI and start a new session.” Following closing the GUI, I can open a new GUI, but when I try to record data, I have high packet loss (greater than 80% loss). I also can’t record data for longer than about 5 minutes without data loss occurring.
Previously, I had issues with the Cyton failing to reconnect with the computer after the initial GUI session was closed. I would usually get a message of “Dongle found but no Cyton board could be located.” I think this issue was resolved by only opening LabRecorder after the LSL streams had been opened in the OpenBCI GUI and PsychoPy. This theoretically ensures the data streams are fully established before LabRecorder tries to start recording them. I also found resetting the dongle and Cyton board using the physical buttons located on them could fix this issue.
However, I still felt this issue was relevant to the conversation because it was also a new issue that didn’t occur last semester, and as such it may be related to the unresolved issues I described above. To solve the issue of packet loss and failure to remain connected, I have tried closing all python programs running in the background in hopes of terminating a previous instance of the GUI that may have remained active. I’ve also tried resetting the hardware using the physical buttons on them. Finally, I’ve tried restarting the computer itself, but I still experience the difficulty with the Cyton+daisy being able to remain connected and record for longer than 5 minutes. I also still experience the related packed loss issue with the data I can record.
Please let me know what I should do next to solve this problem.
Comments
Hi SHatch,
I interspersed a few blank lines in your single paragraph original post, to make it a bit easier to read.
Do you have any idea what changed between last year when everything worked fine, and this year? For example could be your lab location, with the new location having more wireless, Bluetooth, cellular gear near your setup?
An initial recommendation we usually make in the case of packet loss, is to move the dongle closer to the Cyton. This can be done with a usb extension cord. Some users drape the cord+dongle over the top of a nearby monitor. That gets it both off the table and away from nearby metal objects (which can attenuate the radio packet signals.)
If this is an issue with Bluetooth environment being congested (for example other Cytons, etc.) you can try changing the radio channel used:
https://docs.openbci.com/GettingStarted/Boards/CytonGS/#5-optional-settings
Expand that section 5 / Optional drop down.
Regards, William