Use key responses as triggers

[mikhail.ordin]

I need to send the trigger according to the response the person gives. The responses are collected using keyboard component of the builder. The 8 allowed keys are from ‘f1’ to ‘f8’. The triggers that I send are very strange and every time different even if participant presses the same response button.

I use different version of the code with the simplest idea, but it does not work:

#this sends the first trigger that is taken from the excel file, and it works fine
parallel.setData(stimul_type)
core.wait(0.1)
parallel.setData(0)

#the second trigger should be sent 8 seconds later, and it should consist of the concatenation of the stimulus #type and the response given by the participant

core.wait(8)
x=key_resp_run1.keys #this should catch what response the participant chose, from f1 to f8
y=stimul_type #this is taken from the excel file
z=str(y)+str(x) #this concatenates the stimulus type and the response, for example,
#if the stimulus type is “4” and the response of the participant is “f5”, I want the trigger 4f5
parallel.setData(z)
core.wait(0.5)
parallel.setData(0)

the triggers which are sent are sometimes 2-digit, sometimes 3-digit, and even if the same stimulus type and response are pressed, the triggers that are sent are different.
I guess, the problem is in the line
x=key_resp_run1.keys #key_resp_run1 is the name of the keyboard component

[Michael]

Please surround python code with backticks

When you include python code on this forum please put triple “backticks” like this ``` on the line before and the line after your code. If you’ve done it correctly then your code will appear in a grey box with correct indentation like this (check the preview of your post on the right hand side before posting it) and other people will be better able to work out what might be right/wrong with your code. if myVal==True: break If you’ve already posted something that didn’t follow this rule th…

Your problem is here:

@mikhail.ordin

parallel.setData(z)

As the API shows (psychopy.parallel - functions for interacting with the parallel port — PsychoPy v2023.2.3), the .setData() function sends one byte. You are feeding it a multi-character string, which by definition will contain more than one byte’s worth of data.

The parallel port is a very low level interface in this day and age. You are literally controlling the voltages on individual lines in a cable. You can’t just send arbitrary information on that old-school channel.