ESP32-driven Roulette Wheel Could Have Used A 555, But That Didn’t Have WiFi

July 18, 2026 by Tyler August No comments

Sometimes you see a project and immediately, before going into the details, your mind throws up the old refrain: “coulda used a 555” — well, [Hulk] actually agrees when it comes to his ESP32-based, 3D printed roulette wheel. The first version did use a 555, but then feature creep kicked in and the final project ended up with an ESP32 instead. We’ve all been there.

The roulette wheel circuit is retained from the 555 version, with the ESP32 providing clock pulses instead of the venerable oscillator chip — it uses a pair of decade counters to create the chase effect of the LED around the wheel. With a handsome printed enclosure, [Hulk] could have stopped there, but then he’d have to keep track of scoring and the like manually like some kind of dark age peasant. It’s the 21st century, we have computers to to that for us!

Now, even though the ESP32 is still driving the LED chase via the decade counters, it can keep track of where the “ball” of light lands, and reports that via WiFi or serial. While it would have been an option to run the whole game on the ESP32. [Hulk] just has those values put into an SQL database on a server, which also runs the game front-end via PHP. The resulting web page lets two players make their bets and track their wins and losses over time. You can see that in action in the video embedded below.

Overkill? Sure, but we suspect [Hulk] already had the equipment and experience to make this the fastest way to get a playable game. There are easy ways to serve web content from an ESP32, but the easiest tool to use is always the one in your back pocket, right?

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Simple Games From A Simpler Time

July 18, 2026 by Elliot Williams 5 Comments

Modern video games are nothing short of amazing. My son and I were playing through the one of the latest Zeldas, which involve a mix of combat and puzzle-solving that’s pretty much the hallmark of the franchise. But the most recent open-world Zelda is simply massive. Made by around 1,000 people at a development expense of $150,000,000, it takes probably 60-80 hours to play through if you’re not rushing, and more if you’re taking it easy. It has layers of game mechanics, and worlds in the sky, on land, and underground. It’s big in every way.

Contrast the games of my youth, which were a lot smaller. Written by a pair of people or maybe a handful, with playtimes in the single-digit hours, and of course fitting in the limited computing resources of the time. But the low-stakes nature of the early phases of the industry meant that software developers could take risks, and many of the games were consequently kinda idiosyncratic in this more innocent time.

I think there’s something to be said for small games. They don’t require a lifestyle commitment just to get through. They can still be fun, without taking all of your time. And honestly, when you’re done with a game quickly, you have more time for other stuff. Granted, some of this spirit lives on in the small indie games of today, but even so, game developers have the big studios’ products in the backs of their minds when they are working on their smaller oeuvres.

We were talking about preserving old games for posterity around Hackaday and on the podcast, and our conversations reminded me of a couple of educational games that, despite their rudimentary graphics, are still pretty good today. Both were electronics related, and both are still playable today thanks to efforts on emulation and software preservation. To get a feel for the 1980’s, give Rocky’s Boots a try. (I like the TRS-80 Color Computer version the best, but that may just be nostalgia.) Most of you grownups out there will get through it in an hour or so.

And if you want a challenge, try Rocky’s harder sequel: Robot Odyssey. If you already have a background in digital circuits, you’ll find it doable. Younger me hit a wall about two-thirds of the way through.

Both of these games stick with me because they taught me something, but also because they were simply quirky in a way that a game can only be when it’s written by a small team of folks who are just having fun programming it. If you pitched “a puzzle game about a raccoon who builds logic circuits to activate robot boots”, the boardroom would look at you like you’re out of your mind. But it’s just exactly the quirkiness and individuality of some of these early games that I cherish the most.

If you find yourself knee-deep in an endless modern game, take a side-quest off into a more naive time, and you’ll appreciate why people are putting efforts into archiving them.

Spidery Drone Goes Near-invisible By Spinning Really, Really Fast

July 18, 2026 by Donald Papp 11 Comments

Researchers demonstrate that something interesting happens when a small drone with a spindly airframe spins at a high speed: it very nearly turns invisible. The spidery device is shown mounted in its launcher in the image above. The dark blur at the rightmost side is an outlet on the wall behind the drone, not motion blur from a moving part.

There’s not much to do about the noise, but a high-speed spin becomes nearly invisible.

It’s called the Phantom Twist, and while we’ve seen single-motor drones that spin around a central axis before, they have always incorporated a wing-like structure or cleverly leverage the magnus effect to generate lift.

There’s not a lot of detail about the Phantom Twist’s hardware design but it appears to use a downward-angled motor for lift, relying on a high-speed control system to maneuver and maintain altitude.

This does away with the need for a wing, at the cost of only being stable while rotating at a high speed. We imagine it is also a touchy design that depends greatly on being balanced just so.

A hand launcher spins the device up before releasing it for flight. The visual effect once it is up and running is pretty striking; see for yourself in the short video, embedded just below.

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A scanning-electron micrograph is shown of a cricket's body, focusing on the head, which has been sliced off just above the eyes.

Cross-Sectioning Crickets With A Femtosecond Laser

July 18, 2026 by Aaron Beckendorf 7 Comments

Unlike most cutting lasers, femtosecond lasers don’t vaporize materials; rather, they produce such short, intense bursts of light that the affected region is ablated without having the chance to heat its surroundings. This makes them good at cutting away material without damaging the surroundings, something [Ben Krasnow] exploited to cut cross-sections of samples while still in a scanning-electron microscope.

In this case, the samples were crickets, and before imaging they had to be prepared. First, the bodies were soaked in glutaraldehyde to cross-link the proteins and stabilize the structure. Next, a series of solvent exchanges replaced the water in the bodies with a low-surface-tension solvent; this meant that during the next step, drying, surface tension wouldn’t distort the crickets’ internal structure. Finally, the insect bodies were charred under argon, which made the bodies conductive and more absorptive to laser light.

The laser itself and the scanning galvo are mounted outside the microscope, and shine in through a transparent window. To protect the detector and electron optics from a spray of ablated carbon, a servo motor swings an aluminium shutter between these and the sample while the laser is active. This caused some mysterious problems during testing: after the first ablation run, the electron microscope’s image would contain so much noise as to be unusable, but it would improve over time. As it turned out, the shutter was painted, and the other side of the paint was getting coated with charged carbon particles. This created a small capacitor which disrupted the electron optics as it discharged. Eventually, after solving this and a few other strange problems, [Ben] was able to take several time-lapse videos of the laser gradually ablating a cricket, 30 microns at a time, revealing its inner structure.

Although scanning-electron microscopes are unfortunately shard to come by, it’s still possible to restore a secondhand microscope or, as [Ben] did, build your own. Femtosecond lasers are yet more inaccessible, though they can be used to replicate themselves.

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Flex Filament Stuck To Your Build Platform? Reach For The Isopropanol

July 17, 2026 by Donald Papp 5 Comments

3D printing has been around long enough that everyone’s heard at least one weird trick regarding 3D prints. [Angus] of [Maker’s Muse] puts a few to the test, and came away with one solid tip for releasing TPU from a build platform to which it has unfortunately welded itself.

Flexible filaments tend to stick too well to build plates, which is why an interface layer like a thin layer of glue stick is called for. But what if one forgets to apply it before starting a print job? That can result in a print that is well and truly stuck. Peeling flex filament off a textured PEI bed is a bad time, because the print can tear and tends to leave little bits behind.

[Angus] heard that applying isopropyl alcohol helps release things in that case, so he gives it a try. Lo and behold, it seems to work! See for yourself at 18:10 in the video and keep it in mind if you end up in a similar situation. The print doesn’t exactly fall off on its own, but it does remain in one piece which is more than one can expect otherwise.

Watching isopropyl alcohol help release a stuck print is reminiscent of the way it also removes hot glue from just about any surface. The trick is getting the alcohol to wick in underneath for best results, and the same seems to be true with releasing TPU from a build plate.

One thing to keep in mind when evaluating tips and tricks from over the years is that the landscape changes. Something that maybe seemed to have potential years ago might not make much sense today. A good example is sugar as a bed adhesive, which [Angus] tries out. What started as an experiment in getting PLA to play better with glass build plates years ago doesn’t really carry over to now, with PEI-coated magnetic build platforms pretty much a solved problem. The more likely result nowadays is just a mess.

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Using Solar Air Heating To Dry Clothes

July 17, 2026 by Bryan Cockfield 24 Comments

About a month ago, [Greenhill Forge] built a few solar panels to collect energy from the sun. Unlike solar photovoltaics, which turn sunlight directly into electricity, these were designed to gather solar thermal energy with air. These types of panels can gather a tremendous amount of energy for a very low cost, and although the first video only went into the theory of their operation, his latest video actually shows us how to use that energy in a practical way.

The video starts by building a new solar panel, using upgraded materials and building methods compared to the previous versions which should improve the efficiency. There’s some data analysis of the performance, but at the end of the video [Greenhill Forge] actually hooks one of these up to a clothes dryer to explore its real-world efficacy. This process involves disconnecting the electric heater, removing one of the blower fans, and building a new flange to accept the heated air from the solar panel. A microcontroller keeps an eye on the incoming air temperature and controls a fan to try to hit the target temperature.

After an hour of drying, the test clothing was completely dry, with the only electricity used to turn the drum in the dryer. This is more than an order of magnitude of reduction in the power needed to dry clothes, which is fairly impressive. [Greenhill Forge] also notes that systems like these could augment off-grid systems not only for clothes drying but for home heating, greenhouse heating, or drying out various crops and that they could reduce strain on an electrical system that otherwise relies on resistive heating methods. There are many ways of building these panels, so be sure to check out his first video for ideas. Continue reading “Using Solar Air Heating To Dry Clothes” →

How Octopuses Hacked Their Ribosome To Become Smart

July 17, 2026 by Maya Posch 5 Comments

A fascinating aspect in evolutionary biology is that of convergent evolution — whereby similar structures and functions evolve independently from each other. The highly advanced nervous system of octopuses is a good example here, displaying levels of intelligence and capabilities far beyond those of other cephalopods and matching that of primates, despite no evolutionary link here. Exactly how octopuses developed this rather unique capability remained a mystery, though recent research by [Rishav Mitra] points at the rather unique ribosomes in these animals.

Ribosomes are the molecular machinery at the core of each cell that enable the synthesis of proteins. Due to their highly crucial role, they tend to remain evolutionary unchanged, which makes the big change observed in the octopus (i.e. order Octopoda) in the form of this H88 rRNA break quite remarkable.

Common octopus (<i>Octopus vulgaris</i>). (Credit: Albert Kok, Wikimedia) — Common octopus (*Octopus vulgaris*). (Credit: Albert Kok, Wikimedia)

This H88 break increases the accuracy of translated proteins, something that is essential for complex nervous systems as it reduces cases of misfolded proteins (proteinopathy). Because of how well-preserved ribosomes are across species, the researchers were able to run a number of experiments including a similar rRNA break in E. coli that confirmed many of the assumptions about how these octopus ribosomes performed.

Since proteinopathy results in misfolded proteins that are either useless or harmful to the organism – as seen in various human diseases – this can especially harm long-lived cells like neurons. Unsurprisingly, we can see a similar change to ribosomes in other animal groups, including that of us primates. Although the reasons for octopuses to develop more complex nervous systems wasn’t due to social pressures but rather to cope with highly complex and dynamic environments, it would seem that both types of environmental pressures led to the same convergent path, with a little ribosomal help.