Living Mirror Lets You Draw Patterns with Reflected Light

A grid of small mirrors stands there, waiting for light to hit them. Then, in perfect harmony, each mirror tilts and swivels around its own axis. Reflected rays move across a neighboring wall or floor. Lines, forms, and full-fledged animations appear to hover in midair when light spots combine to form them. Time Sink Studio created the Living Mirror, which transforms ordinary sunlight or a spotlight into programmed doodling.

Each mirror is 50 millimeters square and made of ordinary glass. They are installed on special 3D printed holders, which use clever ball-and-socket joints to swivel smoothly in two directions. Cheap stepper motors shove and pull the mirrors to modify angles very accurately, providing thousands of tiny steps for precision control.

The units are grouped into fours and all share a single control board. These boards use some very fancy DRV8825 drivers to control the motors, as well as shift registers to keep the wiring neat as the array grows. At the center of it all is an ESP32 microcontroller that sends instructions via a wireless network. It all works on a conventional 12-volt power source, so you could easily power it with a battery if you needed to use it outside.


It all comes together with some clever software, which is managed by the ESP32 firmware, to ensure that all motor motions run smoothly and on schedule. There is also a web interface that allows anyone to design and draw patterns in a browser; you don’t need to be a coding genius to utilize it. Users can just sketch a shape or sequence, and the system will translate it into the appropriate mirror movements. However, in order to get it exactly right, you must first calibrate it, which requires you to point a camera to the surface you’re projecting onto. The OpenCV software in the browser examines where each reflected beam lands and generates a set of corrections for each mirror, allowing the system to match what you wanted with what is actually happening. That is the portion that truly closes the gap.


Once calibrated, the array comes to life, with light bouncing off the mirrors and zipping about in perfect time. Because of a trick called persistence of vision, our eyes see moving dots as steady pictures, resulting in hearts, spirals, lettering, or basic animations on the target surface. Currently, they are employing 36 mirrors, but should they increase to 64 or more, it opens up a whole new universe of detailed work. Next up is some clever sensor technology that allows you to interact with the setup by following hand motions or tracking your face. If you’re outside on a clear day, sunlight works great for creating soft drawings, however indoors, a focused spotlight or laser enhances the effect. The nicest part is that it can function as a conventional mirror when not in use.


The entire project’s code is available on GitHub for anyone to review and experiment with. This project demonstrates that with a minimal kit, you can design something that redirects light for a practical purpose and creates some very spectacular displays simply by using reflections.
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