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1352 Articles

DIY Your Own Red Light Therapy Gear

March 18, 2025 by 104 Comments

There are all kinds of expensive beauty treatments on the market — various creams, zappy lasers, and fine mists of heavily-refined chemicals. For [Ruth Amos], a $78,000 LED bed had caught her eye, and she wondered if she could recreate the same functionality on the cheap.

The concept behind [Ruth]’s build is simple enough. Rather than buy a crazy-expensive off-the-shelf beauty product, she decided to just buy equivalent functional components: a bunch of cheap red LEDs. Then, all she had to do was build these into a facemask and loungewear set to get the same supposed skin improving benefits at much lower cost.

[Ruth] started her build with a welding mask, inside which she fitted red LED strips of the correct wavelength for beneficial skin effects. She then did the same with an over-sized tracksuit, lacing it with an array of LED strips to cover as much of the body as possible. While it’s unlikely she was able to achieve the same sort of total body coverage as a full-body red light bed, nor was it particularly comfortable—her design cost a lot less—on the order of $100 or so.

Of course, you might question the light therapy itself. We’re not qualified to say whether or not red LEDs will give you better skin, but it’s not the first time we’ve seen a DIY attempt at light therapy. Continue reading “DIY Your Own Red Light Therapy Gear” →

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.

Continue reading “Cheap Fiber Optic Wand Toy Becomes Tiny Weird Display” →

Powerful Flashlight Gets Active Air Cooling

February 9, 2025 by 17 Comments

LEDs were once little more than weedy little indicators with low light output. Today, they’re absolute powerhouses, efficiently turning a flow of electrons into a searing beam of light. Despite their efficiency, they can still put out a fair whack of heat. Thus, if you’re building a powerful flashlight like [CrazyScience], you might wanna throw some active cooling on there just to keep things happy. Check out the video below.

The build will not be unfamiliar to any casual observer of the modern DIY flashlight scene. It uses a flatpack LED module of great brightness and a wad of 18650 lithium-ion cells to provide the juice to run it. The LED itself is mounted in a 3D-printed frame, which leaves its rear exposed, and a small PC fan is mounted for air cooling. It’s not the most optimized design, as airflow out of the fan is somewhat restricted by the 3D-printed housing, but it’s a lot better than simple passive cooling. It allows the torch to be more compact without requiring a huge heatsink to keep the LED at an acceptable temperature.

The final torch doesn’t have the most ergonomic form factor, but it does work. However, as a learning project for a new maker, it’s a start, and the learning value of building something functional can’t be understated. If your desire for flashlights swerves to the more powerful, we’ve covered those, too. Just be careful out there.

Continue reading “Powerful Flashlight Gets Active Air Cooling” →

Tensegrity construction with Adafruit led strands

The Jell-O Glow Tensegrity Toy You Didn’t Know You Needed

January 30, 2025 by 5 Comments

If you’re looking to add a pop of glowing whimsy to your workspace, check out this vibrant jiggly desk toy by [thzinc], who couldn’t resist the allure of Adafruit’s NOODS LED strands. [thzinc]’s fascination with both glowing LEDs and levitating tensegrity designs led to an innovative attempt to defy gravity once again.

The construction’s genius is all about the balance of tension across the flexible LED strands, with three red ‘arms’ and a blue ‘hanger’ arm supporting the central hub. [thzinc]’s early designs faced print failures, but by cleverly reorienting print angles and refining channel designs, he achieved a modular, sturdy structure. Assembly involved careful soldering, tension adjustments, and even a bit of temporary tape magic to perfect the wobbling equilibrium.

But, the result is one to applaud. A delightful, wobbly desk toy with a kind of a Jell-O vibe that dances to your desk’s vibrations while glowing like a mini neon sign. We’ve covered tensegrity constructions in the past, so with a little digging through our archives you’ll be able to find some unique variations to build your own. Be sure to read [thzinc]’s build story before you start. Feel free to combine the best out there, and see what you can bring to the table!

Continue reading “The Jell-O Glow Tensegrity Toy You Didn’t Know You Needed” →

Interactive LED Matrix Is A Great Way To Learn About Motion Controls

January 21, 2025 by 4 Comments

It’s simple enough to wire up an LED matrix and have it display some pre-programmed routines. What can be more fun is when the LEDs are actually interactive in some regard. [Giulio Pons] achieved this with his interactive LED box, which lets you play with the pixels via motion controls.

The build runs of a Wemos D1 mini, which is a devboard based around the ESP8266 microcontroller. [Giulio] hooked this up to a matrix of WS2812B addressable LEDs in two 32×8 panels, creating a total display of 512 RGB LEDs. The LEDs are driven with the aid of an Adafruit graphics library that lets the whole display be addressed via XY coordinates. For interactivity, [Giulio] added a MPU6050 3-axis gyroscope and accelerometer to the build. Meanwhile, power is via 18650 lithium-ion cells, with the classic old 7805 regulator stepping down their output to a safe voltage. Thanks to the motion sensing abilities of the MPU6050, [Giulio] was able to code animations where the LEDs emulate glowing balls rolling around on a plane.

It’s a simple build, but one that taught [Giulio] all kinds of useful skills—from working with microcontrollers to doing the maths for motion controls. There’s a lot you can do with LED matrixes if you put your mind to it, and if you just start experimenting, you’re almost certain to learn something. Video after the break.

Continue reading “Interactive LED Matrix Is A Great Way To Learn About Motion Controls” →

Photo of 3D Tetris LED matrix

From Retro To Radiant: 3D Tetris On A LED Matrix

January 21, 2025 by 8 Comments

We love seeing retro games evolve into new, unexpected dimensions. Enter [Markus]’ adaptation of 3D Tetris on a custom-built 3x3x12 RGB LED matrix. Developed as a university project, this open-source setup combines coding, soldering, and 3D printing. It’s powered by an ESP32 microcontroller with gameplay controlled by a neat web interface.

This 3D build makes the classic game so much harder to play, that one could argue whether it’s still a game, or has turned into a form of art. Although it is challenging to rotate and drop blocks on such a small scale, for die-hard Tetris fans (and we know you’re out there), there is always someone up to become best at it. Just look at the FastLED-powered light show, the responsive web-based GUI, and fully modular 3D printed housing, this project is a joy to look at even when nobody is playing it. Heck, a game that turned 40 only a year ago should be so mature to entertain itself, shouldn’t it?

From homemade Pong tables to LED cube displays, hobbyists keep finding ways to give classic games a futuristic twist. Projects like this are about pushing boundaries. Hackaday’s archives are full of similar innovations, but why not craft some new ones?

Continue reading “From Retro To Radiant: 3D Tetris On A LED Matrix” →

Fluid Simulation Pendant Teaches Lessons In Miniaturization

January 13, 2025 by 7 Comments

Some projects seem to take on a life of their own. You get an idea, design and prototype it, finally build the thing and — it’s good, but it’s not quite right. Back to the drawing board, version 2, still not perfect, lather, rinse, repeat. Pretty soon you look around to discover that you’ve built ten of them. Oops.

That seems to be the arc followed by [mitxela] with this very cool fluid simulation pendant. The idea is simple enough; create a piece of jewelry with a matrix of tiny LEDs that act like the pendant is full of liquid, sloshing about with the slightest movement. In practice, though, this project was filled with challenges. Surprisingly, [mitxela] doesn’t seem to number getting a fluid dynamics simulation running on a microcontroller among those problems, at least not to a great degree. Rather, the LED matrix seemed to cause the most problems, both in terms of laying it out on the 25-mm diameter PCB and how to address the LEDs with relatively limited GPIO on the STM32 microcontroller. The solution to both was diagonal charlieplexing, which reduces the number of vias needed for the 216-LED matrix and allows the 0402 to be densely packed, along with providing some tolerance for solder bridging.

And then there’s the metalworking heroics, which no [mitxela] project would be complete without. This seems to be where a lot of the revisions come from, as the gold-plated brass case kept not quite living up to expectations. The final version is a brass cup containing the LiR2450 rechargeable battery, a magnetic charging connector, and the main PCB, all sealed by a watch crystal. The fluid simulation is quite realistic and very responsive to the pendant’s position. The video below shows it in action along with a summary of the build.

If you want to catch up on [mitxela]’s back catalog of miniaturized builds, start with his amazing industrial ear adornments or these tiny matrix earrings. We’re also fond of his incredible shrinking MIDI builds. Continue reading “Fluid Simulation Pendant Teaches Lessons In Miniaturization” →