This “Mirror” Is Made From a Whole Bunch of LEDs

If you managed to make it to the 2019 Maker Faire at the Great Lakes Science Center in Cleveland, Ohio, then you may have seen a very cool electronic “mirror” on display. That was created by Alex of the Super Make Something YouTube channel, and it was a big hit at the event. The large display shows a reflected image on an array of LEDs, which results in a fun bit of interactive art. Alex recently uploaded a video to the Super Make Something YouTube channel that explains in great detail how this LED mirror was made.

The mirror display has a total of 576 LEDs that are arranged in a 24x24 grid. Each and every one of those is a WS2812b individually-addressable LED — commonly referred to by the Adafruit NeoPixel brand name. That means that each pixel in the array can be a unique color, but this display works best when it shows a single color with varying brightness to generate a monochrome image. But because the hardware has that capability, you could follow this same guide to build a multi-colored display.

All of those LEDs are controlled by a single Raspberry Pi single-board computer. The nice thing about WS2812b LEDs is that a lot of them can be controlled via a single data wire, which keeps wiring nice and simple. That said, these LEDs will draw a lot of power — potentially up to 34.5 amps if every LED is set to white and full-brightness. The voltage drop is also substantial across the chain, which will result in the LEDs at the end of the line being faded. The solution is to use a beefy power supply and connect it at multiple points across the grid.

The LEDs are diffused with 3D-printed covers that were made from translucent PLA. Those diffusers are held in place by laser-cut wood frames. At the very center of the grid there is a small opening for the Raspberry Pi Camera to poke through. A Python script running on the Raspberry Pi grabs an image from that camera and translates each pixel into a brightness setting for the corresponding LED. That process is repeated very quickly, so the mirror updates in real time. The resolution may be low, but it still looks very nice.