Tic-tac-toe is normally played with a pen and paper, or perhaps with a physical marker, but maker “techiesms” has put a new spin on this classic pastime.
His build, as seen here, takes the form of a wooden box that mounts onto the wall with nine square sections arranged in a grid pattern. Players take turns, activating a square by moving their hand near an IR proximity sensor inside each one.
The squares then light up green or red depending on the player, and when a line is made, the system beeps and blinks on and off to signify a winner. Everything is controlled via an Arduino Mega, along with a custom PCB for wiring.
More details on the game and its construction can be found in techiesms’ post here.