Etch-A-Selfie

July 30, 2019 by Bryan Cockfield 5 Comments

Taking a selfie before the modern smartphone era was a true endeavor. Flip phones didn’t have forward-facing cameras, and if you want to go really far back to the days of film cameras, you needed to set a timer on your camera and hope, or get a physical remote shutter. You could also try and create a self portrait on an Etch a Sketch, too, but this would take a lot of time and artistic skill. Luckily in the modern world, we can bring some of this old technology into the future and add a robot to create interesting retro selfies – without needing to be an artist.

The device from [im-pro] attaches two servos to the Etch a Sketch knobs. This isn’t really a new idea in itself, but the device also includes a front-facing camera, taking advantage of particularly inexpensive ESP32 Camera modules. Combining the camera features with [Bart Dring]’s ESP32 Grbl port is a winner. Check the code in [im-pro]’s GitHub.

Once the picture is taken, the ESP32 at the heart of the build handles the image processing and then drawing the image on the Etch a Sketch. The robot needs a black and white image to draw, and an algorithm for doing it without “lifting” the drawing tool, and these tasks stretch the capabilities of such a small processor. It takes some time to work, but in the end the results speak for themselves.

The final project is definitely worth looking for, if not for the interesting ESP32-controlled robot than for the image processing algorithim implementation. The ESP32 is a truly versatile platform, though, and is useful for building almost anything.

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Hackaday Podcast 015: Going Low Frequency, Robotic Machines, Disk Usage For Budgets, And Cellphones Versus Weather

April 19, 2019 by Mike Szczys 6 Comments

Hackaday Editors Mike Szczys and Elliot Williams discuss the highlights of the great hacks from the past week. On this episode we discuss wireless charging from scratch, Etch-A-Sketch selfies, the robot arm you really should build yourself, bicycle tires and steel nuts for anti-slip footwear, and bending the piezo-electric effect to act as a VLF antenna. Plus we delve into articles you can’t miss about 5G and robot firefighting.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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What Can You Learn From An Eggbot?

April 17, 2019 by Elliot Williams 32 Comments

An eggbot is probably the easiest introduction to CNC machines that you could possibly hope for, at least in terms of the physical build. But at the same time, an eggbot can let you get your hands dirty with all of the concepts, firmware, and the toolchain that you’d need to take your CNC game to the next level, whatever that’s going to be. So if you’ve been wanting to make any kind of machine where stepper motors move, cut, trace, display, or simply whirl around, you can get a gentle introduction on the cheap with an eggbot.

Did we mention Easter? It’s apparently this weekend. Seasonal projects are the worst for the procrastinator. If you wait until the 31st to start working on your mega-awesome New Year’s Dropping Laser Ball-o-tron 3000, it’s not going to get done by midnight. Or so I’ve heard. And we’re certainly not helping by posting this tutorial so late in the season. Sorry about that. On the other hand, if you start now, you’ll have the world’s most fine-tuned eggbot for 2020. Procrastinate tomorrow!

I had two main goals with this project: getting it done quickly and getting it done easily. That was my best shot at getting it done at all. Secondary goals included making awesome designs, learning some new software toolchains, and doing the whole thing on the cheap. I succeeded on all counts, and that’s why I’m here encouraging you to build one for yourself.

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Etch-A-Snap Will Sketch Your Selfies

April 12, 2019 by Lewin Day 9 Comments

The Etch-a-Sketch was a hugely popular toy in the days before video games and the Internet became ubiquitous. These days, they’re a fun amusement, but can still be difficult to master. Rather than learn the necessary skills himself, [Martin Fitzpatrick] decided to build a machine to draw for him. Enter the Etch-a-Snap.

The build starts with a Raspberry Pi Zero, equipped with the requisite camera. Images taken are processed into a 100×60 pixel image with 1-bit color. At this stage, a network graph representation is built of the image and used to generate commands for the plotting mechanism to draw the scene. Plotting is achieved with stepper motors that turn the knobs through 3D-printed gears. Plotting is slow, with images taking 15 minutes to an hour to “develop”. The system can also be used to draw manually processed images, which can improve results when images are chosen carefully.

It’s a project that combines modern hardware with a classic toy for some interactive fun. We could imagine a large-scale version of this being a great installation at a science museum or MakerFaire. We’ve seen others tackle a computer-controlled Etch-A-Sketch, too. Video after the break.

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Dad’s Custom Xbox Adaptive Controller Build For His Child

November 21, 2018 by Drew Littrell 3 Comments

When Microsoft announced the Xbox adaptive controller earlier this year, many were pleasantly surprised at how adaptive it truly was. The controller features 3.5mm jacks for easily connecting any external input device and sports an impressive build quality given its price tag, but the most impressive part was the fact that the design was so open in nature. Rather than seeking to create a specific design solution tailored to a subset of users the adaptive controller acts more as a hub for the community’s designs. One of those brilliant designs comes from [Colton] who posted a five-part series on his custom controller build for his daughter.

His daughter, Ellie, has Cornelia de Lange syndrome which prevents her from being able to use more conventional pressure sensitive input devices. So [Colton] devised a way for buttons to be pressed using an alternate range of motion. By attaching foam massage inserts to standard paint rollers, the buttons could be triggered by allowing the peaks and valleys of the foam to roll over the top of each button. He could achieve even better accuracy by attaching braided ribbon over the buttons in order to prevent binding.

After finding that setup to be successful, [Colton] went about designing a frame. He arrived at using PVC pipe and utilizing tees as anchor points for the rollers. A couple of steel hose clamps are enough to hold each of the foam rollers in place, and the contact distance can be dialed in with buttons housed in threaded PVC adapters (shown right). After the addition of a little colored wrap here and there the build has a decidedly cheery exterior.

However, the build was not complete without a custom piece of software to match. [Colton] reached out for help from his nephew to program a “RGB Etch-a-Sketch” they called Sundoodler. The game runs on a small form factor PC hooked up to a projector so Ellie can play lying down. [Colton] has some future plans for his daughter’s custom Xbox adaptive controller build, but for now you can see the results in the video below.

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Using E-Paper Displays For An Electronic Etch A Sketch

November 9, 2018 by Al Williams 12 Comments

Electronic things are often most successful when they duplicate some non-electronic thing. Most screens, then, are poor replacements for paper. Except, of course, for E-paper. These displays have high contrast even in sunlight and they hold their image even with no power. When [smbakeryt] was looking at his daughter’s Etch-a-Sketch, he decided duplicating its operation would be a great way to learn about these paper-like displays.

You can see a video of his results and his findings below. He bought several displays and shows them all, including some three-color units which add a single spot color. The one thing you’ll notice is the displays are slow which is probably why they haven’t taken over the world.

The displays connect to a Raspberry Pi and many of the displays are meant to mount directly to a Pi. The largest display is nearly six inches and some of the smaller displays are even flexible. It appears the three color displays were much slower than the ones that use two colors. To combat the slow update speeds, some of the displays can support partial refresh.

The drawing toy uses optical encoders connected to the Raspberry Pi. The Python code is available. Even if you don’t want to duplicate the toy, the comparison of the displays is worth watching. We were really hoping he’d included an accelerometer to erase it by shaking, but you’ll have to add that feature yourself. By the way, in the video, he mentions the real Etch-a-Sketch might work with magnets. It doesn’t. It is an aluminum powder that sticks to the plastic until a stylus rubs it off.

We’ve seen these displays many times before, of course. If you are patient enough, you can even use them as Linux displays.

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Bot Makes Etch A Sketch Art In One Continuous Line

September 28, 2018 by Dan Maloney 17 Comments

Introduced in 1960 for the princely sum of $2.99 ($25.00 today), Etch A Sketch was to become a standard issue item for the Baby Boomers’ toy box. As enchanting as the toy seems, it’s hard to see why it had staying power: it was hard for young fingers to twirl the knobs, diagonal lines and smooth curves required a concert pianist’s fine motor control, and whatever drawings we managed to make were erased at the slightest jostle of the tablet.

Intent on righting these wrongs, [Sunny Balasubramanian] not only motorized an Etch A Sketch, but he’s also given it a mind of its own in a way. For those unfamiliar with the toy, it’s basically a manual X-Y plotter that drags a stylus across the underside of a glass screen, scraping off a silver powder clinging to the glass to make dark lines. Replacing the knobs with steppers is straightforward, of course, but driving them is the trick. [Sunny] hooked his up to a Raspberry Pi and wrote some Python code to drive them. The Pi also accepts input image files and processes them for rendering through the plotter, first doing Canny edge detection in OpenCV, then plotting a single path through the largest collection of connected pixels in the image. From there it’s just a matter of spinning the motors to create surprisingly detailed images. Check out the short video below to see it in action.

It’s hardly the first automatic Etch A Sketch we’ve seen – here’s one that automates everything including the shake to erase the drawing. That one cheats a little though, in that it rasters across the screen like a CRT. We really like how this one just does a single path. Pretty clever.

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