[Mpark's] propeller controlled Etch-a-Sketch is well built and very accurate. He was inspired by the Step-a-Sketch project and he’s carried that design through to a stunning conclusion. The driver board was built around a Parallax Propeller P8X32A microcontroller. But this isn’t just a serial controller board for connecting the hardware to a PC running CNC software. He’s included TV out and a keyboard port so that programming can be done on the chip itself.
In the video after the break you can see how precise the plotting is on the Etch-a-Sketch. It is well mounted but also benefits from some software compensation for the toy’s imprecise controls. [Mpark] has also included an erase function that tilts the frame upside-down a few times. This is used not only to erase a drawing but to hide the line created when moving the stylus into its starting position.