@paulasaavedra, I send both the trigger and EEG signal via separate LSL streams and merge them in Lab Recorder (it writes everything to one XDF file). I did not try to use accelerometer channels becau

@marles77 thanks for share. Do you send a trigger via LSL? that's what i need to do. I have thought that the best option is to send it through the channels of the accelerometer, so as not to lose one

The external trigger data is then received in the three 'Aux' channels of Cyton. These replace the Accelerometer when the Cyton is placed into 'digital' or 'analog' read mode.

I plan to use the Cyton board in a psychological experiment. To ensure precise timing of events on the EEG, the OpenBCI system needs to receive a TTL trigger from a stimulus presentation computer (tri

Cyton has 8 EEG data channels and 3 'Aux' channels that can record trigger / marker information. These Aux channels can be set to either 'digital' (0V or 3.3V) or 'analog' (10 bit value in that same 0

External trigger documentation is here:

Thank you for your replies, I'm slowly getting to understand everything. The "external trigger" sounds useful. Does this mean that, for example, an external optical tracker could be connecte

PI or Arduino to send an "External Trigger" directly to the Cyton via a wire (connected through an OptoIsolator to remove noise). The data received by the computer will have this trigger pe

Any time you send a trigger from an external device (with power) to the Cyton, it's imperative to use an OptoIsolator.

2) I was having an interference from the digital signal (see Figure 4, but after extensive search on the forum, I think using a coax and an optoisolator may have resolved it, please let me know if the

This uses a photodiode to establish a trigger directly in-line with the data from the Cyton itself.

[paragraph at above link:] Once you have connected, you may selected the "Digital Read" for one of your widgets. Then select start digital read mode button in the top left of the newly popul

Here is a more complete example of what is possible using a photodiode as an external trigger for Cyton.

"External Triggering The Harder Way (Firmware 1.x.x)" once I am using a photodiode as a trigger.

[From that section:] Once you have connected, you may selected the "Digital Read" for one of your widgets. Then select start digital read mode button in the top left of the newly populated w

The Cyton data stream contains the 8 'normal' channels, used for EEG, ECG, EMG, etc. Then it has 3 additional channels, called 'Aux', Auxiliary channels. These are typically used for external trigger

Button press events can already be recorded using the External Trigger feature:

Did you look at the External Trigger section of the docs? On Cyton the 3 channels that by default carry accelerometer data (x, y, z), can instead record external analog or digital signals of your choo

for data collection, is there any automatic trigger available in openbci which can do the synchronization or do I need to do it manually using aux ports?

My hunch is that MindAffect might work possibly also with this camera view idea. HOWEVER, in bright sunlight, that is going to wash out the ability of MindAffect to trigger the cVEP response. Might wo