The Etch A Sketch Live Stream

Even with its clunky controls and low-res, single-color display, the classic Etch A Sketch remains an absolute fan favorite. There is an undeniable charm to spinning those knobs and guiding a single, unbroken line across the screen that beats a standard pad and pencil any day. This appeal has also made it a favorite target in the hardware hacking scene, inspiring everything from automated drawing robots to strange retro computer peripherals.

Last year, YouTuber Tekavou put a new spin on the classic toy with a creation he called the Teka-Sketch. Instead of just modding the original plastic shell, he completely re-engineered the toy from the ground up. The Teka-Sketch is completely digital, with an E Ink display that clears without shaking. That’s a major change, but it still stays true to its roots by drawing every image as a single, continuous, unbroken line.

Tekavou also created a camera that can snap an image, translate it into a single, unbroken line, and display the result on the Teka-Sketch. Now, he has taken this one step further by displaying video streams captured by the camera. This is essentially the same thing Tekavou was doing previously, except images are displayed one after the next. But it needs to go really fast for this to work well, and that wasn't easy to pull off.

The upgraded system required a major overhaul of both the hardware and software pipeline. Generating a single continuous path for one still image already takes a significant amount of processing time. Scaling that process to video rates meant the machine would have to calculate dozens of uninterrupted line paths every second, which was previously impossible.

To make it work, Tekavou rewrote the rendering software to operate across a 12-core host computer, allowing multiple frames to be processed in parallel instead of one at a time. The camera acts as an edge-processing device, handling early frame analysis before transmitting compressed metadata streams to the more powerful server for final rendering.

A classic animation trick also helped to speed things up. Rather than recalculating every part of every frame, the software divides incoming footage into small grid sections and compares them against the previous frame. Areas that remain mostly unchanged are ignored completely, dramatically reducing the amount of work required for motion scenes with static backgrounds.

All of this number crunching really heated things up. The camera hardware suffered a catastrophic thermal failure that melted part of the enclosure. In response, the original prototype was completely rebuilt. Tekavou redesigned the chassis with large passive ventilation openings and moved the battery pack into an external handheld module connected by a cable.

With the hardware fixed up, the system was working perfectly. The video is displayed on a computer rather than the Teka-Sketch hardware, presumably because the E Ink display refresh rate is too low. In any case, seeing a video that is composed of Etch A Sketch images is very cool. But am I the only one who was a little disappointed that Tekavou didn’t play the video for Take On Me by A-ha on his new creation?