estimated reading time: 2 min

Few toys are more iconic than the Etch A Sketch, which has been popular for 65 years now. In that time, more than 100 million units have been sold worldwide. And every single one of them has had the same problem: the lack of an “undo” button. If you mess up your masterpiece, your only choice is to give the Etch A Sketch a good shake and start over. That’s an unavoidable result of the Etch A Sketch’s drawing mechanism, which Tekavou overcame by building a digital “Teka-Sketch.”

An Etch A Sketch is a two-dimensional manually operated cable-driven plotter with a stylus that scrapes a whitish aluminum powder off the screen, leaving a transparent line that looks dark because the interior of the enclosure is unlit. When you shake the whole thing, the aluminum powder sticks back onto the screen and “erases” the entire drawing. That mechanism doesn’t leave room for a simple solution for erasing portions of lines, which is why complex drawings induce so much anxiety.

The Teka-Sketch is a digital device and it can arbitrarily draw or erase lines in whatever manner its programming dictates. In this case, Tekavou kept it simple and mimicked most of the functionality of an Etch A Sketch. There are still two knobs to control movement of the virtual stylus in the X and Y axes, and it still draws straight darkish lines on a whitish background. The big change is the introduction of an “undo” button (clicking the left knob), which erases the most recent few centimeters of the line.

The key component in the Teka-Sketch is an Inkplate 6 from a brand called Soldered Electronics. The basic unit combines a high-quality 6” e-paper display with an ESP32 microcontroller, and there are also packages available with an enclosure and battery. Tekavou simply added a couple of rotary encoders and packed everything into a custom 3D-printed enclosure. Everything else was coding, which Tekavou first started learning as a kid after discovering NIBBLES.BAS —a Snake variant programmed in QBasic.

As an homage to that formative experience, Tekavou created a Nibbles game that runs on the Teka-Sketch. It even has a two-player mode, with two onscreen snakes (one controlled by the left knob and one controlled by the right knob). E-paper screens are notorious for poor refresh rates, which is why they aren’t more common, but the Inkplate 6’s screen has partial refresh rates fast enough to make the game perfectly playable.

Now Tekavou’s own kids can share some of the experiences he had as a child, but in a way that has been improved with technology.

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