Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Supported by

Eye tracking tobii T120

Hi, I am currently working with a tobii t120 and OpenSesame 3.2.7 (Python 2.7.13), using a Windows 7 32bit. It is the first time that I use both and I am having problems with pygaze_init.

When I try to run the experiment, I receive the following Error message:

What does this error message means and is there a solution to this problem?

Your help will be very helpful!!



  • Hi Simone,

    It looks like the Tobii Pro SDK can't find you tracker. Is the T120 compatible with the Pro SDK? (And is it licensed for that?)

    If the Pro SDK doesn't work, you could try the tobii-legacy backend, which doesn't require the Pro SDK.

    Good luck!


  • In case it is compatible and licensed, here's my $ 0.02. We had experienced a similar issue with a Tobii Spectrum. This is related to the way in which the SDK automatically looks for eyetrackers and theoretically selects the first available one. For us, this threw an error, because a different Tobii eyetracker had previously been connected. My suspicion is that this is cached in wherever libtobii looks for it.

    Our solution/workaround (that's a fine line) was to use libtobii's first method and add the serial number of our eyetracker to the settings.

  • edited July 2019

    Hi Edwin and cesco,

    I'm having the same issue as Simone, and I am running on the same eyetracker. I am very new to both eyetracking and Pygaze and was hoping to get more information about three things mentioned on this thread (e.g. 1. The Pro SDK license, 2. libtobii's first method, and 3. tobii-legacy backend):

    1. I found that the T120 is compatible with the Pro SDK, but I wasn't sure how to find out if the eyetracker is licensed for it. Is there a way to find out if it is?
    2. Would there be a good way to use libtobii's first method? I am very new to Pygaze and am not sure where/how to add the eyetracker serial number to the settings.
    3. Is there a good way to troubleshoot errors that read "No module named tobii.eye_tracking_io.basic," when using the tobii-legacy backend? I got this error when trying to use the tobii-legacy backend. I have read through some previous threads, but I haven't been able to resolve this issue either.

    Thank you so much for any help!

    Edit: I resolve the issue I was having using the method cesco suggested!

  • Answering for future reference:

    1. You'd have bought this license from Tobii, so I think you would probably know if you had the Pro SDK.
    2. If you have the Pro SDK, you can choose "tobii" in the pygaze_init item's drop-down menu. (This is all you have to do.) If you'd like to use Cesco's method, you should add TRACKERSERIALNUMBER to the settings by doing the following in an inline_script's Prepare phase all the way at the start of your experiment: from pygaze import settings; settings.TRACKERSERIALNUMBER = # (but instead of "#" you'd put in your serial number.)
    3. That means you don't have the old Tobii Python package installed! There's a copy included in the portable Python environment provided here:
Sign In or Register to comment.