Hacked Gadgets Forum

January 10, 2010

Step-a-Sketch – PIC 16f84a based CNC controlled Etch a Sketch Toy

at 7:59 am. Filed under Cool Gadgets, DIY Hacks, Electronic Hacks, Funny Hacks, Game Hacks


This Step-a-Sketch project is sure to bring back some memories if you are around my age. I remember having one of these growing up, I think I got it for a Christmas present one year. Unfortunately it was killed when I was going through my how does this work phase. Almost everything with screws around me got taken apart, some were even put back successfully. By using a PIC 16f84a microcontroller tied to a home made unipolar stepper driver Chris from Powered By Nerd was able to allow a computer is able to send CNC pulse data to the PIC and the PIC then controls the stepper motors to draw a 2D image on the Etch a Sketch. We have seen a similar project before and the same project in reverse, something about a toy from my childhood brought to life with modern electronics that is a pleasure to see. If you want to build one for yourself Chris has provided the code and schematic to give you a head start.

Thanks for the tip Jeff.

“This code works fine, but it would need some work before it’s connected to an industrial machine.  The most glaring problem is that the PIC will not take the same amount of time to execute the code every pass through the program, due to whether or not one or both of the motors have been instructed to move.  This could also account for some of the hesitation I occasionally see.  An easy solution to this would be to add delay loops into the code, when no real work needs to be done.”