Have you ever tried to draw something with an Etch-A-Sketch?  If you’re like me, a basic rectangle is about as ambitious as you can get.  However, a while back I built a harmonograph table that creates interesting drawings using pendulums swinging back and forth to control a pen (they’re pretty cool – do a quick Internet search for “harmonograph” and check out the pictures!).  Then, I saw my son’s Etch-A-Sketch lying around the house and thought, I could connect motors to that to turn the two knobs back and forth with precision to replicate the geometric drawings on the Etch-A-Sketch.  And, surprisingly, it worked pretty well (after numerous failures and revisions…).

So, I decided to get a little more ambitious and try to get the Etch-A-Sketch to replicate simple drawings (and sometimes not so simple).

I use a Raspberry Pi Zero W microcomputer (the “Pi”) to process the image, determine a path, and control the motors.  The Pi also serves up a simple wireless interface for user control, and it controls a third motor that can rotate the Etch-A-Sketch to erase it between drawings.  The idea was to make it entirely “hands-free.”

The video below shows it in action – first the original harmonograph figures and then pictures, including a time-lapse at the end of the drawing of an entire image from start to finish.

Come check it out in person at the next Asheville Maker Faire!