Makers have long known that ping pong balls make great diffusers for LEDs, but now, using individual RGB LED PCBs, Tjjensma has taken things to a whole new level and created ping pong ball clock. This device, which uses an Arduino Nano clone and an RTC module for accurate timekeeping, involved daisy-chaining well over 100 LED modules together to form the display.
The clock itself — meant to hang on a wall — looks like a sort of stretched-out hexagon, with sloping side pieces and a long middle to display hours and minutes, along with a colon to separate everything. Woodworking involved is simple, though effective. Wiring seems fairly straightforward, but actually soldering all the LEDs together had to be quite a bit of work
One note Tjjensma gives us from the experience (repeated several times) is not to use cheap “ping pong” balls that appear to be toys, not actually meant for any sort of actual competition. Once this issue was sorted out though, the results are spectacular, with a glow that from the photos looks like they were illuminated with a black light. On the other hand, it’s notoriously hard to get an accurate picture of LEDs, so perhaps you should “simply” build one yourself to see how it looks!