Connect Four (sometimes marketed as “Connect 4”) was first published by Milton Bradley in 1974. It’s a two-player game where the players take turns dropping discs into a grid. The goal of the game is to get four of your discs in a line vertically, horizontally, or diagonally. It’s a fun game that can be quite challenging despite the deceptively simple rules. Unfortunately, the fun doesn’t last long before you inevitably lose some of the discs. Kelly Bodeman and Jack Whelan used an Arduino to create an electronic Connect Four game that ditches those discs entirely, and they have posted an Instructables tutorial explaining how you can build your own.
The rules of this version are exactly the same as traditional Connect Four. The game board is divided up into a grid of seven columns and six rows. Instead of channels that plastic discs drop into, this has a grid of ping pong balls. Each of those ping pong balls contains an individually-addressable RGB LED. Those are normally turned off, but light up when a player drops a virtual disc in a column. They select the desired column by pushing one of the seven arcade buttons on the base of the device, and the next “open” position will light up with that player’s color.
The lights are controlled by an Arduino Uno board, which also monitors the arcade buttons. The beautiful enclosure was made from a combination of 3D-printed parts and acrylic sheets, with aluminum bar bent to form the stand. The ping pong balls are used to diffuse the light from the LEDs. In addition to the basic game logic, Bodeman and Whelan also programmed animations for each disc dropping down and for a winning game. The finished electronic Connect Four looks fantastic, and would be perfect for a day care or a bar top at a brewery.