If you want to create a large display with a matrix of LEDs, it’s a relatively straightforward process. Thanks to addressable LED tape and microcontrollers it becomes more of a software issue than one of hardware. [Vincent Deconinck] had some inexpensive WS2812 strips, so he sliced into an inexpensive IKEA coffee table and mounted them in a grid beneath an acrylic sheet. Some work with Arduino Nanos and a Raspberry Pi later, and he had a very acceptable LED matrix table.
An attractive hack, you might say, and leave it at that. But he wasn’t satisfied enough to leave it there, and so to make something rather special he decided to add interactivity. With an infra-red emitter and receiver as part of each pixel, he was able to turn an LED table into an LED touchscreen, though to be slightly pedantic it’s not sensing touch as such.
The design of the IR sensors was not entirely straightforward though, because to ensure reliable detection and avoid illumination from the LED they had to be carefully mounted and enclosed in a tube. He also goes into some detail on the multiplexing circuitry he used to drive the whole array from more Arduinos and a GPIO expander.
The write-up for this project is a long one, but it’s well worth the read as the result is very impressive. There are several videos but we’ll show you the final one, the table playing touch screen Tetris.