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.

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RC Batwing Actually Flies

Batman is a compelling superhero for enough reasons that he’s been a cultural force for the better part of a century. His story has complex characters, interesting explorations of morality, iconic villains, and of course a human superhero who gets his powers from ingenuity instead of a fantastical magical force. There are a number features of the Batman universe that don’t translate well to the real world, though, such as a costume that would likely be a hindrance in fights, technology that violates the laws of physics, and a billionaire that cares about regular people, but surprisingly enough his legendary Batwing jet airplane actually seems like it might be able to fly.

While this is admittedly a model plane, it flies surprisingly well for its nontraditional shape. [hotlapkyle] crafted it using mostly 3D printed parts, and although it took a few tries to get it working to his standards, now shoots through the air quite well. It uses an internal electric ducted fan (EDF) to get a high amount of thrust, and has elevons for control. There are two small vertical stabilizer fins which not only complete the look, but allow the Batwing to take to the skies without the need for a flight controller.

Not only is the build process documented in the video linked below with some interesting tips about building RC aircraft in general, but the STL files for this specific build are available for anyone wanting to duplicate the build or expand on it. There are plenty of other interesting 3D-printed models on [hotlapkyle]’s page as well that push the envelope of model aircraft. For some other niche RC aircraft designs we’ve seen in the past be sure to check out this F-35 model that can hover or this tilt-rotor Osprey proof-of-concept.

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An Enigma Machine Built In Meccano

As far as model construction sets go, LEGO is by far the most popular brand for building not only pre-planned models but whatever the builder can imagine. There are a few others out there though, some with some interesting features. Meccano (or Erector in North America) is a construction set based around parts that are largely metal including its fasteners, which allows for a different approach to building models than other systems including the easy addition of electricity. [Craig], a member of the London Meccano Club, is demonstrating his model Enigma machine using this system for all of its parts and adding some electricity to make the circuitry work as well.

The original Enigma machine was an electronic cypher used by the German military in World War 2 to send coded messages. For the time, its code was extremely hard to break, and led to the British development of the first programmable electronic digital computer to help decipher its coded messages. This model uses Meccano parts instead to recreate the function of the original machine, with a set of keys similar to a typewriter which, when pressed, advance a set of three wheels. The wheels all have wiring in them, and depending on their initial settings will light up a different character on a display.

There are a few modifications made to the design (besides the use of a completely different set of materials) but one of the main ones was eliminating the heavy leaf springs of the original for smaller and easier-to-manage coil springs, which are also part of the electrical system that creates the code. The final product recreates the original exceptionally faithfully, with plans to create a plugboard up next, and you can take a look at the inner workings of a complete original here.

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A LEGO CNC Pixel Art Generator

If you are ever lucky enough to make the trip to Billund in Denmark, home of LEGO, you can have your portrait taken and rendered in the plastic bricks as pixel art. Having seen that on our travels we were especially interested to watch [Creative Mindstorms]’ video doing something very similar using an entirely LEGO-built machine but taking the images from an AI image generator.

The basic operation of the machine is akin to that of a pick-and-place machine, and despite the relatively large size of a small LEGO square it still has to place at a surprisingly high resolution. This it achieves through the use of a LEGO lead screw for the Y axis and a rack and pinon for the X axis, each driven by a single motor.

The Z axis in this machine simply has to pick up and release a piece, something solved with a little ingenuity, while the magazine of “pixels” was adapted with lower friction from another maker’s design. The software is all written in Python, and takes input from end stop switches to position the machine.

We like this build, and we can appreciate the quantity of work that must have gone into it. If you’re a LEGO fan and can manage the trip to Billund, there’s plenty of other LEGO goodness to see there.

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A LEGO Orrery

We aren’t sure how accurate you can get with LEGO, but a building block orrery looks cool, if nothing else. [Marian42] saw one done a few years ago and decided to build a version with a different mechanism. At first, the plan was to use some 3D printed fixtures, but the final product is made entirely from LEGO bricks. Very impressive. The video below shows that it has been complete for awhile, but the write-up that goes into great detail has only just arrived and it was worth the wait.

This is one of those things that seems simple if you don’t think too hard about it. However, when you sit down to actually do it, there are a number of challenges. For one thing, the Earth tilts at 23.5 degrees, and as the planet rotates, the tilt stays in the same direction, making it tricky to model mechanically.

The moon also has a 5.15 degree inclination, but since that’s hard to notice at this scale, the LEGO orrery exaggerates it. So, the Moon’s track has its own set of design problems. The whole thing has to rotate on a concentric shaft, which is also tricky to get right with kids’ building blocks.

Compared to the last orrery we saw, this one is huge. We’ve always been partial to ones that you have to look up to.

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The end result of the build, a supersized ultrasonic sensor, held in a person's hands

A Super-Size Functional Tribute To An Ultrasonic Sensor

Sometimes, it’s time to shut down the oscilloscope, and break out the cardboard and paints. If you’re wondering what for, well, here’s a reminder of an Instructable from [CrazyScience], that brings us back to cardboard crafts days. They rebuild one of the most iconic components for an electronics tinkering beginner — an ultrasonic distance sensor, and what’s fun is, it stays fully functional after the rebuild!

This project is as straightforward as it gets, describing all the steps in great detail, and you can complete it with just a hot glue gun and soldering iron. With materials being simple cardboard, aluminum foil, popsicle sticks, some mesh, and a single ultrasonic sensor for harvesting the transmitter and receiver out of, this is the kind of project you could easily complete with your kids on a rainy day.

Now, the venerable ultrasonic sensor joins the gallery of classics given a size change treatment, like the 555 timer we’ve seen two different takes on, or perhaps that one Arduino Uno. Unlike these three, this project’s cardboard skeleton means it’s all that simpler to build your own, what’s with all the shipping boxes we accumulate.

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Etch-A-Sketch Camera Is Open Source

The Etch-a-Sketch was a great toy if you were somehow born with the talent to use it. For the rest of us, it was a frustrating red brick filled with weird grey sand. [Every Flavor of Robot] has taken the irritating knob-encrusted oblong and turned it into something we can all enjoy, however, by building an Etch-a-Sketch camera!

The build is simple. It uses an ESP32 microcontroller to run the show, equipped with a camera. The camera is used to take a photo of the subject, and the image is then sent to a desktop computer. The desktop runs the image through an AI pipeline that generates a simplified version of the image, and the necessary G-Code to draw it on the Etch-A-Sketch. The toy’s knobs are operated by a pair of brushless motors which have been geared down to provide more torque.

It’s a neat project, and more details are available on GitHub. We’ve seen some other great mechanized Etch-a-Sketch builds before, too.

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