Maker Sean Heber has constructed an digital equal to an Etch A Sketch toy — however determined to take the good distance round, creating it on breadboards from discrete logic chips with out the good thing about a microcontroller.
“It isn’t truly an actual Etch A Sketch. in fact,” Heber admits of his creation, “however it sort of works like one — besides as a substitute of utilizing pulleys and belts it makes use of electrical energy and wires, and as a substitute of grey aluminum powder my display screen is made from LEDs.”
The unique Etch A Sketch launched in 1960, constructed by the Ohio Artwork Firm and based mostly on L’Écran Magique (The Magic Display) designed by inventor André Cassagnes. Successfully a hand-driven XY plotter, the toy is managed utilizing a pair of knobs to maneuver a stylus utilizing a sequence of pulleys and belts — scraping a layer of aluminum powder from the display screen, rendering elements clear. Resetting the gadget after you have drawn one thing is as easy shaking the toy to coat the display screen as soon as extra.
Heber’s model drops the mechanical elements and powdered aluminum in favour of electronics — managed, just like the analog unique, utilizing two knobs at both aspect of the show. Stated show is a quartet of 8×8 single-color LED matrices, although it isn’t linked to a microcontroller; as a substitute, Heber opted to make use of timing circuits based mostly across the traditional 555 and discrete logic chips to learn the rotary encoder inputs and transfer a cursor across the display screen — leaving a glowing drawing in its wake.
The show circuitry was put in on a chunk of perfboard, hiding the lots of wires beneath. (📷: Sean Heber)
“[It works] by displaying bits from the RAM one pixel at a time, lots of of occasions per second [and] our regular persistence of imaginative and prescient will likely be sufficient to make it seem like a strong picture,” Heber explains of the circuit. “This venture was in all probability approach past my digital ability stage after I began it, however I am actually completely satisfied that I managed to tug it off anyway. All in all, it took over a month to determine my strategy and to get all of the elements that I wanted.”
The construct is documented in full within the video embedded above and on Heber’s YouTube channel.