This project is an updated version of the original reaction timer project described in Len Buckwalter's "Electronic Games & Toys You Can Build" book. The incandescent bulbs and passive components are replaced by a microcontroller and LEDs.
Step 1: The Original Reaction Timer
This is the original reaction timer game. The purpose of the game is to see who has the fastest reaction time. A golf ball is placed at the top of the rail and allowed to roll downhill until it hits a stop. The first person to press his button AFTER the ball hits the stop is the winner. If a player presses his button before the ball reaches the end, he loses.