I made an interactive Eitech crane to put in the shopwindow of my technical-toyshop in Numansdorp in Holland. Instead of using the controller that comes with it, I took an Arduino and three light-sensors and made the crane controllable thrue the shop window.
The controls are not perfect yet, but this is how it works.
The kids love it.
I'm still working on the code.
(this is my first instructable and I'm still learning how it works)