RoboSketch - Propeller controlled Etch-a-Sketch

[JasonDorie]

While this is much simpler than Mike Park's PropEtcher (see http://www.youtube.com/watch?v=MgyZgqImAHA) it was as much a test of my CNC machine cutting acrylic as it was making an automated Etch-a-Sketch.



The circuit is incredibly simple: it's a Protoboard and a single darlington array to control a pair of unipolar stepper motors (the ones Parallax sells here: http://www.parallax.com/StoreSearchR...5/Default.aspx)

I used my home-built CNC router to cut the face plate and gears from a single piece of acrylic and replaced the existing red frame with my new CNC'd one.

The software is written entirely in SPIN and supports a simple "goto" function that takes an X & Y coordinate. It uses a Bresenham line algorithm to control the step rate of the motors. With gearing and using 1/2 steps, the usable screen area is about 800 x 600 units.

Here's a video of it in action: http://www.youtube.com/watch?v=W3iPjJfIIOs
...and another of it drawing the Hack-a-Day logo: http://www.youtube.com/watch?v=-MNqW1GT4nc

Code is attached.

[PJ Allen]

Dorie, you've done it again!

(Show it making the Spirograph pattern.)

[RonP]

Nice work Jason.

Does this mean your back to writing code for Quadracoppters? Joking of course.

Ron

[JasonDorie]

PJ - Better still - I made it draw a skull & crossbones... er, wrenches. It's the Hack-a-Day logo.

[PJ Allen]

Super.
It's a cinch to get on then.

[PJ Allen]

You did it!

http://hackaday.com/2011/08/05/etch-...to-hack-a-day/

[JasonDorie]

I sent it to them - I figured drawing their logo would help. It's interesting to see the other ones that have been done in the past.