I'm confused about this. I observed artifacts when I was using the simple photoresistor. I am using it as an external trigger for synchronization in a traditional p300 matrix speller to mark on/off wh

another electronic device) that is sending the trigger synchronization, as an on/off electrical signal. Please use the schematic shown in those links, they are both the same. There is also no need fo

The photoresistor (photodiode + 2 resistors) is similar to the link you posted. That was without the optoisolator but i did measure interference. Do you have any link that shows how to connected the o

Some related monitor trigger links:

Why have you connected the external trigger ground to the Cyton ground?? The whole purpose of the optoisolator is to optically isolate the two circuits.

And this is using a different screen (trigger is every 200ms here), which is weird cause it seems trigger is only in 2 of the channels.

Frankly however, I think you would be BETTER OFF, reading out your external triggers in Analog mode than digital. Then your code can confirm that the trigger on/off voltage levels are what you expect.

I'm seeing artifacts in my signal too. I'm using a photoresistor with an optoisolator (as in https://docs.openbci.com/Cyton/CytonExternal/) connected in pin D13. Using it for P300-based applications.

Would it be possible to use EMG with a cyton board to trigger an alarm? It would require having the algorithm integrated and a buzzer connected.

The optoisolation section of the External Triggering document, can apply to all firmware versions. It is just a method of electrically isolating the trigger source from Cyton PIC32 input pins. When yo

I hope you are well. I tried to resolder the J3 and J4 myself and tried to input the trigger in the different pins from D11 - D18. However, I cannot see any input in the Other channels (there are 6 &q

re: firmware changes needed for external trigger.

I am just a beginner and hope somebody can help out. I am trying to input some external triggers into the openBCI for each auditory stimulus but I am struggling with this tutorial: https://docs.openbc

Hello,

I am looking to access the A6 channel which I have attached to an external trigger to use during a cognitive experiment. It would be ideal if I could access the analog channel data when saved in BDF f

As mentioned before, keep all your trigger wires FAR away as possible from the electrode wires. Also you can try to MINIMIZE the current flowing in your trigger wires, by using appropriate values of r

button and 4.5v of batteries as the external trigger. The setup successfully registers the button press but still creates significant artifacts in the EEG signal upon both press and release. I'm not

The GUI recording is writing a Brainflow structure. Check the column headers. Although the 'Aux' data fields (three 16 bit values in the radio packets) do indeed share contents with either Acceleromet

When plotting, the analog data is simply shown as a flat line, with none of the analog spikes present which I can see when playing back the same data on OpenBCI GUI. I noticed that the y-axis of these

between a left or right image, will also send a triggers to OpenBCI/OpenBCI GUI. I'm not sure of the possibility of this working, but there is a Mouse function in Arduino that allows for mouse inputs