20€ DIY-Eyetracker for school projects

If you plan to use this project for secondary school students, you can ask them to do the video analysis in Python3 with the help of openCV. There are some fascinating tutorials out there explaining all the needed steps.

Usually, it's getting the image frame, convert to grayscale, using a filter to reduce noise, then running the analysis. You can either convert further to black and white and crop the image, so the only moving black spot is the iris, or you can look for circular shapes, and then check if their size is in the region that makes sense for an iris.

The parameters of black-white conversion or size of circles to look for, depends on tests you have to do yourself, using your build version...

Here's s short screenshot with different outputs from the sample code (check github link):

The sample code prints the x/y coordinates of the circle(s) found to the console for further inspection. Congratulations, your students now have successfully reduced complex pictures to x/y coordinates of the eye moving! From here they can easily build own applications for the eye tracker!

Here is a short demo of the code... it uses the slower "live mode" of the software, so the reaction of the robot is not immediate.
Uploadmode (program runs on robot) and communication back to the computer (running the image processing) is not possible for all robots, that's why the slower mode is used here...

On May 23rd I will be visiting a primary school in Austria, and we will build several eyetrackers with 3rd grade students. These will be simple version ones, though, and we plan to build and do a first coding within 60minutes. The school is very much focussing on topics of medical support and "medical engineering", students are using 3d-printer and even laser cutter with assistance of their teachers.

I will publish some photos and maybe a short video here... A first short demo was successful in a secondary school in Berlin. But now I don't have an endoscopic camera left, so all images are taken by the "advanced" version of the eyetracker.