Hackaday Podcast 029: Your Face In Silver Sand, Tires Of The Future, ESP32 All The CNC Things, And Sub In A Jug

Hackaday Editors Elliot Williams and Mike Szczys geek out over the latest hacks. This week we saw a couple of clever CNC builds that leverage a great ESP32 port of GRBL. The lemonade-pitcher-based submarine project is everything you thought couldn’t work in an underwater ROV. Amazon’s newest Dot has its warranty voided to show off what 22 pounds gets you these days. And there’s a great tutorial on debugging circuits that grew out of a Fail of the Week. Plus, we get the wind knocked out of us with an ambitious launch schedule for airless automotive tires, and commiserate over the confusing world of USB-C.

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 (58 MB)

Places to follow Hackaday podcasts:

Continue reading “Hackaday Podcast 029: Your Face In Silver Sand, Tires Of The Future, ESP32 All The CNC Things, And Sub In A Jug”

Etch-A-Selfie

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.

Continue reading “Etch-A-Selfie”

Etch-A-Snap Will Sketch Your Selfies

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.

Continue reading “Etch-A-Snap Will Sketch Your Selfies”

The Complete Beginner’s Guide To Building A CNC Machine

Despite appearances, [This Old Tony]’s latest series has little to do with CNC-ifying an Etch A Sketch. Although he certainly achieves that, more or less, automating the classic toy is just the hook for a thorough lesson in CNC machine building starting with the basics.

Fair warning: we said basics, and we mean it. [Old Tony]’s intended audience is those who haven’t made the leap into a CNC build yet and need the big picture. Part one concentrates on the hardware involved – the steppers, drivers, and controller. He starts with one of those all-in-one eBay packages, although he did upgrade the motion controller to a Mach4 compatible board; still, the lessons should apply to most hardware.

By the end of part one, the Etch A Sketch is connected to two of the steppers and everything is wired up and ready to go for part two, the first part of which is all about inputs and outputs. Again, this is basic stuff, like how relays work and why you might need to use them. But that’s the kind of stuff that can baffle beginners and turn them off to the hobby, so kudos to [Old Tony] for the overview. The bulk of the second part is about configuring Mach4 Hobby, with a ton of detail and some great tips and tricks for getting a machine ready to break some end mills.

For someone looking to get into a CNC build, [Old Tony]’s hard-won CNC experience really fills in the gaps left by other tutorials. And it looks like a third part, dealing with making all this into something more than an automated Etch A Sketch, is in the works. We’re looking forward to that.

Continue reading “The Complete Beginner’s Guide To Building A CNC Machine”

Etch-a-Sketch 3D Printed With Cell Phone

Most of us have fond memories of the Etch-a-Sketch from childhood. [Potent Printables] wanted to update the designs so he 3D printed an XY carriage for a stylus that works with a cell phone drawing program. You can see the video below and the 3D model details on Thingiverse.

The design is fun all by itself, but it also gave us a few ideas. For one thing, if you motorized it you could make some pretty clever drawing toys. But there could be a more practical use, too.

Continue reading “Etch-a-Sketch 3D Printed With Cell Phone”

Using E-Paper Displays For An Electronic Etch A Sketch

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.

Continue reading “Using E-Paper Displays For An Electronic Etch A Sketch”

Bot Makes Etch A Sketch Art In One Continuous Line

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.

Continue reading “Bot Makes Etch A Sketch Art In One Continuous Line”