Makers can be broadly separated into two groups: those who like to build practical technology, and those who like to use practical technology to build something fun. Practical pursuits are, of course, very noble, and we’re always impressed by the innovations makers achieve in that arena. But, there is a special place in our hearts for projects that are just plain weird. Lukas Stratmann’s Floating Eye in a Jar falls squarely into the latter category.
Stratmann created this strange disembodied eyeball for a Raspberry Pi technology and arts seminar in Germany. The “eyeball” is a painted ping pong ball that floats in the water inside of a jelly jar. That would be disconcerting in its own right, but that’s obviously not all it does. In addition to simply bobbing in the water, it turns to follow motion it detects in the immediate area. There is nothing touching the eyeball other than the water, and it doesn’t have any means of propulsion — so how does it move?
The jelly jar sits on a platform, and underneath that platform is a Raspberry Pi Zero W. The Raspberry Pi controls a servo that has magnets attached to the servo arm. Inside of the ping pong ball are magnets on a 3D printed mount. So, when the servo moves, the eyeball turns with it. A camera on the front of the base is used to capture video, and OpenCV uses that to detect where motion is happening in the frame. The result is exactly what it looks like: a sinister eyeball that follows you as you move.