Prize Wheel Angle Sensor 

This career fair demonstration uses a smart angle sensor and an Arduino to track the rotation of a prize wheel and create a cool optical illusion.
Key ASR-Series sensor specifications are: 0.1 degree precision; various interface options; wide field operating range; high speed; full temperature range; and ultraminiature.
Here is a link to more information about the sensor we used:
www.nve.com/we...
And the breakout board:
www.nve.com/we...