Electronic Etch-A-Sketch, No Microcontroller Required

In a lot of ways, Etch-A-Sketch is the perfect toy; simple, easy to use, creative, endlessly engaging, and as a bonus, it’s completely mechanical. We find that last attribute to be a big part of its charm, but that’s not to say an electronic version of the classic toy can’t be pretty cool, especially when it’s done without the aid of a microcontroller.

This is one of those “because I can” projects that we always find so interesting, and more so because it wasn’t entirely clear to [BigZaphod] that he had the skills to pull it off. While his initial design centered around a bunch of 8×8 LED matrix displays and a 256×4-bit RAM chip, the rest of it was a lot of hand-waving. After a few experiments with addressing the LEDs, [Zaphod] started filling in the blanks with a refresh circuit using a 555 — naturally — and a pair of counters. Properly debounced encoders for the horizontal and vertical controls came next, along with more counters to track the cursor and a host of other circuits that ended up looking like a “one of each” selection from the 7400-series catalog.

While we do wish for a schematic on this one, it’s still a pretty enjoyable video, and the end product seems to work really well. The electronic version has a few features the original lacks, such as wrapping the cursor to the other side of the screen. We’d imagine that the buttons on the encoders could be put to work, too; perhaps a click could make it so you can move the cursor without leaving a trail behind. That might be a challenge to execute in logic, but then again, that was the point of the whole thing.

Still jonesing for that mechanical Etch-A-Sketch experience? Not a problem.

8 thoughts on “Electronic Etch-A-Sketch, No Microcontroller Required

    1. Depends. How “neat” do you consider an entire development environment and programming devices for an FPGA to be?

      Sometimes we confuse complexity for simplicity when everything is packed away neatly behind an install script.

  1. The natural platform for this would be e-ink panels. They already have a shift register for horizontal and vertical sides, and a pin to pulse to write a pixel. Though only a few displays have a direction control line for the shift registers, the ones that do would only need a quadrature encoder -> step/dir conversion.

  2. Great, fun project for learning. With a schematic, it’d also be a great project for teaching!
    Yes, it would be easier, neater, cheaper, etc to use a microcontroller, but those are the goals of this project. Personally, I think this is awesome.

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