If you have the external trigger onset recorded simultaneously with your EEG stream, then you have precise alignment of the stimulus with the resulting EEG. You should not need to assume there are 187

If you have the ability to use the Aux data for external triggers source, why not just place a trigger at appropriate points of your audio presentation? Using an external trigger is the best solution,

I checked how many sample lengths are recorded through brainflow while sending external trigger of 60 seconds to cyton, and it's increased by 20 samples on average ( theory :125*60 = 7500 samples / ac

Understandable! I will acquire one of these tomorrow and observe the output trigger from the Optoisolator under an oscilloscope to verify this as per your suggestion. Thank you.

If I try to trigger using an Arduino, it works fine, without any issues.

I obtained the suggested part (CNY17F-3) and made the circuit. There are still no noticeable triggers from RPi. I have tried everything possible including checking the wiring, the wires etc., but it d

Yes, I am recording external trigger events in the EEG data stream.

Rafia, is this a BCI application? What does the subject see/hear, and what are good / bad trials? Are you recording external trigger events in the EEG data stream?

I made the circuit as per the link that you have shared and it does not recognize the GPIO triggers from my RPi on the OpenBCI GUI. Do you have any suggestions on how I can move past this?

The thing is, I think it was deprecated to have better accuracy about "focus" detection, but for our project we don't really care about the status of being "focused" and if the per

* trigger an action if alpha waves are detected 

https://www.google.com/search?as_q=p300+trigger&as_sitesearch=openbci.com

My approach to trauma is much like yours, as a sufferer. Examining the field of techniques on offer raised a question, how come there's a dozen techniques and one mechanism? I'd already resolved a sin

Update: I now realize a few things from digging through the forum and other communities. The Java timer won't do due to imprecision, the Cyton allows for external triggering, and for the Ganglion I'd

Since your binary on/off state of the trigger pin, needs basically only one bit to report -- you could then possibly stuff that trigger bit into the high order bit position of one of the X, Y, Z accel

Is the digital read signal with external triggering accurate enough to detect P300, so long as I don't use the accelerometer?

So there is currently no support to multiplex between board modes automatically. For example by only returning Accel data 10 times per second or 5 times per second, etc. And at other sample times, ret

If your event has a digital or analog output signal, then it could received as an "external trigger", this is recorded simultaneously with the 8 data channels. Using the 'Aux' channels, 3 of

Direct EEG channel -> MIDI note (with amplitude mapped to note volume and note trigger)

Here is the version I made, which includes an LED light to help with visual confirmation of a trigger: