Trigger type

Mojtaba

Hi,

In my new fNIRS (functional Near Infrared Spectroscopy) experiment, I need to send triggers in the form of "letter+[space]" such as "A " (never understood why the Hitachi system accepts only this crazy trigger type!) via the serial port.

I am aware about the possibility of sending numbers as trigger in the OpenSesame, but I wonder whether there is any way to send the triggers in the form of "letter+[space]" by the OpenSesame.

Thanks ahead for your support.

Cheers,
Mojtaba

PS: I have switched to the OpenSesame for almost all the neuro and behavioral experiments that I run now; so, I appreciate your valuable work.

sebastiaan

Hi Mojtaba,

What kind of triggers do you want to send? That is, are you using the parallel port, the serial port, or something else? (A trigger as such is not a specific thing. It's just a generic term for a signal that you sent to some device.)

PS: I have switched to the OpenSesame for almost all the neuro and behavioral experiments that I run now; so, I appreciate your valuable work.

Good to hear!

Cheers!
Sebastiaan

Mojtaba

Hi Sebastiaan,

We could actually solve the problem
The trick was to add these lines of codes in the inline_script:

1. to connect to the Hitachi fNIRS via the serial port (in the "Prepare" tab in the inline_script)
   import serial
ser = serial.Serial('COM1')

2. to send the triggers on the onset of the trials in the form of "letter+[space]" (in the "Run" tab in the inline_script)
   ser.write(bytes(self.get('trigger') + ' '))

3. to send the triggers on the offset of the trials in the form of "letter+[space]" (in the "Run" tab in the inline_script)
   ser.write(bytes(self.get('trigger') + ' '))
ser.close()

I hope this information will be helpful for the others as well

Cheers,
Mojtaba

PS1: in the Hitachi fNIRS system, we need to send the triggers for both onset and offset of each trial.
PS2: I would like to give the credit of this work to my assistant, Alexander Derksen.