We have seen quite a few automated Etch-a-Sketch machines in our time, but when [Jason] wrote in to share his take on the subject, it came with a nice bribe attached. We are vain. It’s not something we are proud of, but when it comes to seeing the Hack a Day logo drawn out by a robot, consider us sold.
[Jason] has several CNC router builds under his belt, and thought it would be fun to automate his Etch-a-Sketch, a toy he loved as a child. He cut some gears and a face plate for the toy with his new CNC machine, then got busy programming his Propeller microcontroller to do his bidding.
A piece CNC software handles the conversion of a bitmap image to an outline, which is then converted to a CNC cutting path. The cutting path is translated into x/y coordinates by a bit of C++ code, before being fed into the microcontroller, which is running a small SPIN application he calls RoboSketch. The Propeller takes care of the rest, quickly drawing the image or pattern to the Etch-a-Sketch.
Continue reading if you would like to see a video of [Jason’s] tribute to Hack a Day, and don’t miss some of our previous automated Etch-a-Sketch coverage if this is something on your to-do list.
[youtube=http://www.youtube.com/watch?v=-MNqW1GT4nc&w=470]
Before hackaday I didn’t know this idiom, but after it had been repeated about 1000 times, I learned it well :D
http://www.google.com/search?q=“do+his+bidding”+OR+”do+your+bidding”+site:hackaday.com+-site:hackaday.com/tag+-site:hackaday.com/category+-site:hackaday.com/page+-site:hackaday.com/author
I love etch-a-sketches too. But during my last raid on the toy shops I couldn’t find any. Are they still produced?
They are still around – I got mine at HobbyTown, but you can order them online from Ohio Art, the original maker of them, Toys-R-Us, etc.
Some toys-r-us have them but only around Christmas.
And nice to see propeller chips being used :)
I wonder if there’s a way to pull the stylus back from the screen so you don’t have to have lines connecting each element.
Not easily – There are a couple videos on the web of taking them apart. The way it’s constructed would make it tricky. Possible, but not trivial.
As I remember them, the construction is not very stiff, everything is springy. I guess one could attach some kind of a string to the stylus and pull the string back with a servo. Another method that was used in some cheap old plotters would be to raise from one side the entire frame that carries the stylus.
I’ve built a few EAS projects, but was disappointed by the quality of the current Chinese made EAS toys, which are much inferior to the older USA made ones… The string movement is jumpy, full of knots that cause erratic behavior and is generally sloppy (the strings would tighten up, then “twang”). I bought and returned several before finding one acceptable to use with any accuracy. The older USA models had much less play and made better candidates, though it is difficult to find one with minimal screen wear.
I had this issue as well – The first one I got was basically unusable in exactly the way you describe. I ordered that one online from Ohio Art. The 2nd I picked up at HobbyTown, and got to make sure it worked well before buying it.