This “Mirror” Is Made From a Whole Bunch of LEDs
Alex recently uploaded a video to the Super Make Something YouTube channel that explains in great detail how this LED mirror was made.
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.