Dry Electrodes & Headband, high impedance with Cyton
I've been trying to use the dry electrodes and headband from the OpenBCI Instructional kit with the Cyton board. What I found is that while the dry electrode provides some signal during the first session, after stopping and starting the session again, the channels with the dry electrodes have 0 voltage and railed impedance readings. We also tried restarting the app, the computer, and the Cyton board, and it still has the same problem. When I swapped the dry electrode for a paste electrode in the same channel, however, the paste electrode would work. I have checked the electrical connections of the dry electrodes with a multimeter and they seem fine, but I cannot seem to get any readings from the Cyton board when I look at the GUI.
We used to do these tests more than a year ago with the exact same hardware (electrodes and board) and it would work. We have also tried with the older version of the OpenBCI_GUI (through Processing 3.5.4), but it also has the same problem.
We are very unsure of what the reasons for this problem are. Do you have any suggestions that we should try to fix this?