According to HackADay’s Kristina Panos, Dodgey99 originally employed two 5V stepper motors with ULN2003 drivers, but ultimately decided to upgrade to faster Nema17 motors driven by an ATmega328 powered kit.
“These [original] motors are mounted on the back and rotate the knobs via pulleys,” Panos explained.
“They are kind of slow; it takes about 2 1/2 minutes to draw the time, but the point of the hack is to watch the Etch-A-Sketch.”
Dodgey99 has already written three sketches for the clock: one to configure the RTC, a test hardware run to sample the look of the digits and the main code to replace the very first test sketch.
“The icing on this timekeeping cake is the acrylic base and mounting he’s fashioned,” said Panos.
“During his mounting trials, he learned a valuable lesson about drilling holes into an Etch-A-Sketch. You can’t shake an Etch-A-Sketch programmatically, so he rotates it with a Nema 17.”
Interested in learning more? You can check out the project’s official Instructables page here.