A brilliant clock made out of 128 LED-lit ping pong balls
Ping pong balls have long been known as excellent LED diffusers, but few have taken this technique as far as Thomas Jensma. His colorful clock features 128 LEDs, arranged in an alternating pattern, and housed in a stretched-out hexagonal wood frame.
Everything is controlled by an Arduino Nano, along with an RTC module for accurate timekeeping. Demos of the clock can be seen below, cycling through numbers and testing out the FastLED library.
Code for the build is available in Jensma’s write-up. This also includes tips on using table tennis balls as diffusers, as well as how to create an orderly array out of these spheres—useful in a wide range of projects.