Author: Zoe Skyforest

3814 Articles

Cheap Fiber Optic Wand Toy Becomes Tiny Weird Display

February 28, 2025 by 11 Comments

If you’ve ever seen those cheap LED fiber optic wands at the dollar store, you’ve probably just thought of them as a simple novelty. However, as [Ancient] shows us, you can turn them into a surprisingly nifty little display if you’re so inclined.

The build starts by removing the fiber optic bundle from the wand. One end is left as a round bundle. At the other end, the strands are then fed into plastic frames to separate them out individually. After plenty of tedious sorting, the fibers are glued in place in a larger rectangular 3D-printed frame, which holds the fibers in place over a matrix of LEDs. The individual LEDs of the matrix light individual fibers, which carry the light to the round end of the bundle. The result is a tiny little round display driven by a much larger one at the other end.

[Ancient] had hoped to use the set up for a volumetric display build, but found it too fragile to be fit for purpose. Still, it’s interesting to look at nonetheless, and a good demonstration of how fiber optics work in practice. As this display shows, you can have two glass fibers carrying completely different wavelengths of light right next to each other without issue.

We’ve featured some other great fiber optic hacks over the years, like this guide on making your own fiber couplings. Video after the break.

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Low-Resolution Fluid Simulation On An ESP32

February 28, 2025 by 2 Comments

Fluid simulations are a key tool in fields from aerospace to motorsports and even civil engineering. They can be three-dimensional and complicated and often run on supercomputer clusters bigger than your house. However, you can also do simple two-dimensional fluid simulations on very simple hardware, as [mircemk] demonstrates.

This build is almost like a simple toy that displays particles rolling around and tumbling as you turn it one way or the other. Behind the scenes, an ESP32 is running the show, simulating a group of particles responding to gravity in a fluid-like manner. The microcontroller is  hooked up with an 3-axis gyroscope and accelerometer, which it uses to track motion and influence the motion of the particles in turn. The results of the simple fluid simulation are displayed on a screen made up of a 16 x 16 matrix of WS2812B addressable RGB LEDs, which add enough color to make the build suitably mesmerizing.

There’s something compelling about turning the display and watching the particles tumble and flow, particularly when they’re all set to different colors. [mircemk] also gave the build the ability to operate in several different modes, running “sand,” “liquid” and “gas” simulations and with dynamic coloring to boot.

We’ve seen some great videos from [mircemk] before, too, like this sensitive metal detector rig. Continue reading “Low-Resolution Fluid Simulation On An ESP32” →

Gonzo Film Making With The Raspberry Pi

February 28, 2025 by 8 Comments

Gonzo journalism has been a hip thing since the 1970s or so, a way of covering a story in a compelling format with more subjectivity and less objectivity. The style has since been applied to all sorts of media, including film—and indeed, the makers of the Gonzo Pi.

The Gonzo Pi is a camera with an open source design, yes, but it’s also a lot more than that. It’s intended to be an entire platform for film-making, all in the one housing. Camera-wise, the design combines a Raspberry Pi with the requisite first-party High Quality Camera, and warps it up in a 3D printed housing. You can build it up with a viewfinder and whatever old-school C-mount or 8 mm film lenses you can lay your hands on.

Beyond that, there’s an editing platform baked in to the device. It’s not unlike the tools in so many social media apps these days. The idea of the Gonzo Pi is that rather than shooting a whole ton of footage and takes and poring over them in great detail later, instead, you run and gun with the device and edit as you go. You can shoot retakes as you need, and even dub in more audio as necessary as you compose your film on the hoof. It’s intended to change the way you make films by virtue of its unique compositional paradigm.

We’ve featured some neat homebrew cameras before, to be sure, but none that quite put the edit suite right in the box.

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Convert A Cheap Tube Preamp Into A Headphone Amp With Jenny

February 27, 2025 by 21 Comments

Big-name tube amplifiers often don’t come cheap. Being the preserve of dedicated audiophiles, those delicate hi-fis put their glass components on show to tell you just how pricey they really ought to be. If you just want to dip your toe in the tube world, though, there’s a cheaper and more accessible way to get started. [Jenny List] shows us the way with her neat headphone amp build.

The build starts with an off-the-shelf preamp kit based around two common 6J1 tubes. These Chinese pentode valves come cheap and you can usually get yours hands on this kit for $10 or so. You can use the kit as-is if you just want a pre-amp, but it’s not suitable for headphone use out of the box due to its high-impedance output. That’s where [Jenny] steps in.

You can turn these kits into a pleasing headphone amp with the addition of a few choice components. As per the schematic on GitHub, a cheap transformer and a handful of passives will get it in the “good enough” range to work. The transformer isn’t perfect, and bass response is a compromise, but it’s a place to start your tinkering journey. Future work from [Jenny] will demonstrate using a MOSFET follower to achieve much the same result.

We’ve seen a great number of headphone amplifiers over the years, including one particularly attractive resin-encased example.

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What Game Should Replace Doom As The Meme Port Of Choice?

February 27, 2025 by 115 Comments

DOOM. The first-person shooter was an instant hit upon its mrelease at the end of 1993. It was soon ported off the PC platform to a number of consoles with varying success. Fast forward a few years, and it became a meme. People were porting Doom to everything from thermostats to car stereos and even inside Microsoft Word itself.

The problem is that porting Doom has kind of jumped the shark at this point. Just about every modern microcontroller or piece of consumer electronics these days has enough grunt to run a simple faux-3D game engine from 1993. It’s been done very much to death at this point. The time has come for a new meme port!

Good Game

Doom became a popular meme port for multiple reasons. For one, it’s just complex and resource-intensive enough to present a challenge, without being so demanding as to make ports impractical or impossible. It’s also been open-source for decades, and the engine has been hacked to death. It’s probably one of the best understood game engines out there at this point. On top of that, everybody plays Doom at some point, and it was one of the biggest games of the 90s. Put all that together, and you’ve got the perfect meme port.

However, you can always have too much of a good thing. Just as The Simpsons got old after season 10 and Wonderwall is the worst song you could play at a party, Doom ports have been overdone. But what other options are there? Continue reading “What Game Should Replace Doom As The Meme Port Of Choice?” →

Too Smooth: Football And The “KnuckleBall” Problem

February 26, 2025 by 25 Comments

Picture a football (soccer ball) in your head and you probably see the cartoon ideal—a roughly spherical shape made with polygonal patches that are sewn together, usually in a familiar pattern of black and white. A great many balls were made along these lines for a great many decades.

Eventually, though, technology moved on. Footballs got rounder, smoother, and more colorful. This was seen as a good thing, with each new international competition bringing shiny new designs with ever-greater performance. That was, until things went too far, and the new balls changed the game. Thus was borne the “knuckleball” phenomenon.

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Pocket Device Tracks Planets And The ISS

February 21, 2025 by 7 Comments

Ever been at a party and landed in a heated argument about exactly where the International Space Station (ISS) is passing over at that very instant? Me neither, but it’s probably happened to someone. Assuming you were in that situation, and lacked access to your smartphone or any other form of internet connected device, you might like the pocket-sized Screen Tracker from [mars91].

The concept is simple. It’s a keychain-sized item that combines an ESP32, a Neopixel LED, and a small LCD screen on a compact PCB with a couple of buttons. It’s programmed to communicate over the ESP32’s WiFi connection to query a small custom website running on AWS. That website processes orbit data for the ISS and the positions of the planets, so they can be displayed on the LCD screen above a map of the Earth. We’re not sure what font it uses, but it looks pretty cool—like something out of a 90s sci-fi movie.

It’s a great little curio, and these sort of projects can have great educational value to boot. Creating something like this will teach you about basic orbits, as well as how to work with screens and APIs and getting embedded devices online. It may sound trivial when you’ve done it before, but you can learn all kinds of skills pursuing builds like these.

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