Everyone under the age of 60 remembers the frustration of trying to generate a work of art on an Etch A Sketch.
The mechanical drawing toy, introduced in 1960 by the Ohio Art Company, features an iconic gray screen, red plastic frame, and two white knobs that move a built-in stylus, displacing aluminum powder to leave a solid line.
"The Etch A Sketch is one of the most frustrating drawing toys from childhood. Can we combine some code and motors to make this toy produce nice pictures?" wondered Sunny Balasubramanian, quantitative researcher by day and hacker by night.
Balasubramanian used the Canny edge detector to outline figures and convert their pixels into a network of connected nodes. Since the Etch A Sketch can't make jumps, though, he tends to focus on the largest available network—say, an elephant among trees and grass. He then connects the dots in a path, which gets converted into a series of steps for the motors to follow.