Make: More Electronics

Chapter 32. Experiment 32: Enhancing Ovid

You’ll remember from Experiment 23 that I wanted a better way to distinguish between one player’s token and the other player’s token when two people are playing Ovid’s Game. At that time, the best I could do was to suggest that each person should identify himself by pressing a button.

With sensors, this is no longer necessary.

Suppose one player uses magnetic tokens while the other player uses nonmagnetic tokens, all of which will fit into the same holes in the playing board. If each hole is equipped with a Hall-effect sensor (which will respond to the magnetic tokens but not to the others), and if each hole also has a transmissive IR sensor (which will respond to all of the tokens), we should be able to ...