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"Could not find a Cedrus device"


I’m using Standard Standalone PsychoPy v3.2.4 with a Cedrus button box (RB-740) on MacOS, Version 10.14.6.

I have an experiment that uses the response box on two separate routines. When I attempt to run the experiment I receive the error: “Could not find a Cedrus device”. If I disable the response box object on one of the routines (for testing), the experiment runs fine. From reading online it seems there is a known issue of attempting to have multiple response box objects in the same experiment. I need more than one routine to allow a testing block before the experimental block.

Does anyone know of a solution/work-around for this problem?

Thank you for any help you can offer,

It is often possible to use the same routine in each of your testing and experimental blocks, just by using loops around them that point to different conditions files. This might be a work-around for you?

Brandon, a “Could not find a Cedrus device” error message usually indicates that the USB driver is not installed. One way to know for sure is to run the Cedrus Xidon software. If Xidon can detect the response pad, then it’s an issue with your PsychoPy script. Otherwise, it’s a USB driver issue.