Battery Holder 3XAAA

555 Timer Ball Whacker

This project uses a simple 555 timer chip and a feedback loop to control a servo-controlled wooden arm. Whenever an object comes close to a photosensor mounted on the end of the arm, it blocks the amount of light detected, which triggers the arm to swat the object away.

Whack-a-Mole Game

Whack-a-Mole Game

Jim Chen designed an excellent electronic “Whack-a-Mole” game using 555 timers, LEDs, and bent-diode touch sensors, that you can build on a solderless breadboard