Connecting the Tobii 4C with a microcontroller

[Marieke De Vylder]

Dear,
I’m a Belgian student an I’m working on my thesis this year. For my thesis, I would like to use the Tobii 4C eye tracker. Normally you have to connect it to the screen, but can I also connect it to a microcontroller without a screen? So could you remove the screen and just look around you and get the coordinates of the points where you are looking at?

If you can’t use a microcontroller to do this and if you then use a laptop/pc, you can get de coordinates of the point on the screen where you are looking at. But I read that you can use a screen with a maximum size of 27″, what if I connect a screen of 15″? Is it then possible to get the coordinates of the points next to and above your 15″ screen if you are looking there (so ‘similating that your screen is 27″‘?)?
So if I connect my pc to this eye tracker, but I’m ‘similating the screen’, is that a possibility?

Thank you in adavance!
Marieke De Vylder

[Grant [Tobii]]

Hi @marieke, and thanks for your query. Indeed the Tobii 4C tracker does depend on a connected monitor to properly work and is not compatible with a microcontroller in the manner you have specified.

There should be no problem in using a monitor of 15″.. the 27″ is just the maximum size over which we can guarantee accuracy so you don’t need to worry about ‘simulating’ a larger size.

Theoretically, you could overlay the 15″ screen itself with the stimulus you want to track.. say a book, or other 2D object.

Please bear in mind however, that the use of the Tobii 4C Eye Tracker for research or data analysis requires the purchase of a special analytical use licence to do so. You can read more about this @ https://analyticaluse.tobii.com/

In any event, if you could kindly describe in more detail your project intentions, we would be better placed to help you.

[Marieke De Vylder]

Dear,

Thanks for the answer! The purpose of my thesis is to make a wheelchair with eyetracking for paralyzed persons for example. So simply said: if the person looks to a certain point, the wheelchair has to move in that direction.

But if I understand it correctly, the point where you are looking at, has to lay at a fixed distance. So my idea now is to make a construction around the wheelchair: you have the eyetracker at a distance of 30 cm above the legs and you have an iron bar with a height of 5 cm just above the eyetracker. This bar has a width of 67.8 cm, which gives us a diagonal of 68 cm ( = 27″). If the person is looking at the bar, I can get the coordinates from the Tobii software. From these coordinates, I can derive in what direction the wheelchair has to move. So the person has to look at the bar to steer the wheelchair.

Do you think this is possible?

Thank you in advance!

Kind regards,
Marieke De Vylder

[Grant [Tobii]]

Hi @marieke, thanks for the extra information on your project intentions. I am afraid that this is rather outside the scope and purpose of the Tobii 4C which is exclusively targeted toward regular interaction with a computer monitor.

If you have already purchased the 4C, then my suggestion would be to consider mounting a small monitor on the wheelchair and develop an application that has ‘zones’ on the monitor that can correspond to movement commands. You would need to include both the Tobii SDK and another SDK that somehow interacts with the chairs electronics, but perhaps that is not so difficult?

Indeed, with this route, as the application itself is purely for interaction purposes, you would not need to purchase the analytical use licence in this case.
I would mention that if you unplug the monitor, then the eye tracker would cease to work also.

Hopefully this workaround might suit your needs?

[Author]

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