How to send markers based on key press?

We have a section in our experiment where participants are supposed to press left or the right arrow key. We would like to send a marker via parallel port whenever the arrow keys are pressed; left arrow= 5, right arrow= 6. We cant seem to tie the marker signal to the key press i.e. the key press is recognized but no markers are sent via parallel port. We have tried utilizing both getKeys, waitKeys.

Hi There!

Please could you share the code snippet that you are using to send the marker? I think you need a conditional that checks on each frame if a key is pressed and “if pressed” then send trigger.


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Can the parallel port components do this?
Or only in code components?

You might be able to use the parallel out component, but if you are using custom code to get the key, and want to send a different trigger based on which key is pressed, it maybe easier to send the trigger using custom code as well.

Are you using an actual parallel port to send the triggers or some other device / hardware?

As @Becca suggested, providing a simplified version of your project, showing what you are trying to do and what is not working as expected, might help us provide more detailed suggestions.

Thank you

Hi,I have alreay fixed this problem in some other hardward. Thanks for you advices.