psychopy.hardware - hardware interfaces

PsychoPy can access a wide range of external hardware. For some devices the interface has already been created in the following sub-packages of PsychoPy. For others you may need to write the code to access the serial port etc. manually.


psychopy.hardware.findPhotometer(ports=None, device=None)[source]

Try to find a connected photometer/photospectrometer!

PsychoPy will sweep a series of serial ports trying to open them. If a port successfully opens then it will try to issue a command to the device. If it responds with one of the expected values then it is assumed to be the appropriate device.

portsa list of ports to search

Each port can be a string (e.g. ‘COM1’, ‘’/dev/tty.Keyspan1.1’) or a number (for win32 comports only). If none are provided then PsychoPy will sweep COM0-10 on win32 and search known likely port names on macOS and Linux.

devicestring giving expected device (e.g. ‘PR650’, ‘PR655’,

‘LS100’, ‘LS110’). If this is not given then an attempt will be made to find a device of any type, but this often fails


  • An object representing the first photometer found

  • None if the ports didn’t yield a valid response

  • None if there were not even any valid ports (suggesting a driver not being installed)


# sweeps ports 0 to 10 searching for a PR655
photom = findPhotometer(device='PR655')
if hasattr(photom, 'getSpectrum'):
    # can retrieve spectrum (e.g. a PR650)

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