July 6th, 2022—
Rob Cai over on Instructables has created his own version of the classic video game Space Invaders using an Arduino Nano. However, unlike most other projects that would typically incorporate some kind of LCD or OLED screen, he chose to use a small black and white cathode ray tube (CRT) display recovered from an old video intercom system.
As his first step, Cai needed to locate the analog-only video input on the salvaged screen as well as find its rated supply voltage. From here, he built a very minimalistic tiny arcade cabinet out of cardboard and used hot glue to join the panels together. But before he could assemble anything, Cai wrote his port of Space Invaders by designing several kinds of 2D sprites and loading them into a few arrays. Outputting a video signal was accomplished via the use of the TVout library, which takes an array of pixels and writes them sequentially to the designated RCA video output pin, as well as syncing each frame with a secondary pin.
The controls for the game are comprised of five buttons, with four on the left for moving in a certain direction, and the last one on the right for firing the player’s laser upwards. For more information about how Cai built this mini Space Invaders arcade cabinet, you can read his guide here or watch the demo video below!