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Cedrus Button Box Component

This component allows you to connect to a Cedrus Button Box to collect key presses.

Note that there is a limitation currently that a button box can only be used in a single Routine. Otherwise PsychoPy tries to initialise it twice which raises an error. As a workaround, you need to insert the start-routine and each-frame code from the button box into a code component for a second routine.


: string
Everything in a PsychoPy experiment needs a unique name. The name should contain only letters, numbers and underscores (no punctuation marks or spaces).
Start :
The time that the button box is first read. See Defining the onset/duration of components for details.
Stop :
Governs the duration for which the button box is first read. See Defining the onset/duration of components for details.
Force end of Routine
: true/false
If this is checked, the first response will end the routine.
Allowed keys
: None, or an integer, list, or tuple of integers 0-7
This field lets you specify which buttons (None, or some or all of 0 through 7) to listen to.
: (choice of: first, last, all, nothing)
Which button events to save in the data file. Events and the response times are saved, with RT being recorded by the button box (not by PsychoPy).
Store correct
: true/false
If selected, a correctness value will be saved in the data file, based on a match with the given correct answer.
Correct answer: button
The correct answer, used by Store correct.
Discard previous
: true/false
If selected, any previous responses will be ignored (typically this is what you want).


Device number: integer
This is only needed if you have multiple Cedrus devices connected and you need to specify which to use.
Use box timer
: true/false
Set this to True to use the button box timer for timing information (may give better time resolution)

See also

API reference for iolab