Interactive Halloween props are always fun. So in this project I designed a simple motion tracking system that will make your Halloween props turn to look at people and follow their movements as they walk by.
To do this, I mounted a servo to the bottom of a foam skull. Then I set up an array of light sensors in front of it. When a person walks in front of it, the light sensors will detect the person's shadow. An Arduino then calculates where they are standing and turns a servo to face them. When they move, the system adjust and turns the skull to face their new position. You can set this up on a shelf or fence where people will be walking by. It stays still until someone is right next to it. You can surprise a lot of people simply because they aren't expecting it to move.
Check out the full build on Make" Projects () and Instructables (/)
Read all about it on MAKE: /