Haciendo un poco de research me topado con varios experimentos de automatización de las pantallas 'Etch-A-Sketch' entre ellos:
Jason Dorie: The circuit is a Protoboard and a single darlington array to control a pair of unipolar stepper motors.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.
Angela Yuan: It uses the Arduino computing platform to control the knobs, which twist to sketch the time, every minute.