Wheel of Fortune sensing approach

Projects General Guidance
1

As a part of a family game I want to make a wheel of fortune.
The wheel of fortune will call out where the wheel has end up with an Arduino MP3 Shield.

What do I have already:

  • Wheel of fortune.
  • Arduino
  • MP3 Shield

The question:
I have 3 ideas on how I can read where the wheel has landed.

    1. A camera who reads an object on the back of the wheel. like a QR-code (disadvantage: Camera has to focus, reaction could be slow??. How does the camera know when the wheel is totally still and has to read the QR?)
    1. Rotary encoder (Is this even possible because people like to use brute force on the wheel sometimes, I think a rotary encoder might be too fragile for that.)
  • Color sensor. Is this accurate enough when you use a lot of colors. How many colors a color sensor can seperate anyway?

Those are just ideas, but I think there must be a better way to read the endup of the wheel.I am not really advanced with programming, so I hope there could be an easy way to read and spit out output with sensors like the ideas I have.

A big Problem part of the project I think, is that he has to start sensing when the wheel has stopped. Maybe a rotary encoder can read that? But I don't know if I can or must apply a rotary encoder to this project.

Maybe someone has enough experience to know what sensing technique I can use best, or has other ideas?!

Thank you for your help already!

2

I would print out a disc for the back with stripey lines. Then put a QRE113 optical sensor looking at the disc. Probably add a second sensor which only has one black line per rotation - this sets the zero point. Then a third sensor only slightly offset from the first to make a quadrature encoder.

Make many more lines than there are possible stops on the wheel. Then you can detect several transitions per stop. When you see it reverse direction when it bounces off the final stop, you can declare the wheel stopped.