Chase Light SAO Shouldn’t Have Used A 555, And Didn’t

March 27, 2025 by Dan Maloney 13 Comments

Around these parts, projects needlessly using a microcontroller where a simpler design would do are often derided with the catch-all “Should have used a 555,” even if the venerable timer chip wouldn’t have been the ideal solution. But the sentiment stands that a solution more complicated than it needs to be is probably one that needs rethinking, as this completely mechanical chaser light badge Simple Add-On (SAO) aptly demonstrates.

Rather than choosing any number of circuits to turn a strip of discrete lights on and off, [Johannes] took inspiration for his chaser lights from factory automation mechanisms that move parts between levels on steps that move out of phase with each other, similar to the marble-raising mechanism used in [Wintergatan]’s Marble Machine X.

Two thin plates with notches around the edge are sandwiched together inside the 3D printed case of the SAO, between the face and the light source. A small motor and a series of gears rotate the two masks 180° out of phase with each other, which creates the illusion that the light is moving.

It’s pretty convincing; when we first saw the video below, we were sure it was a row of tiny LEDs around the edge of the badge.

Hats off to [Johannes] for coming up with such a clever mechanism and getting it working just in time for Hackaday Europe. If you need to catch up on the talks, we’ve got a playlist ready for you.

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LED Filaments Become Attractive Time Piece

March 25, 2025 by Lewin Day 39 Comments

There are a million ways to use LEDs to make a clock. [sjm4306] chose to go a relatively conventional route, making something that approximates a traditional analog timepiece. However, he did it using LED filaments to create a striking and unique design . Thus the name—FilamenTIME!

LED filaments are still relatively new on the scene. They’re basically a bunch of tiny LEDs mounted in a single package to create a single “filament” of light that appears continuous. It’s great if you want to create a bar of light without messing around with populating tons of parts and having to figure out diffusion on your own.

[sjm4306] used them to create glowing bar elements in a clock for telling the time. The outer ring contains 60 filaments for the 60 minutes in an hour, while the inner ring contains 12 filaments to denote the hours themselves. To handle so many LEDs, there are 9 shift registers on board. They’re driven by an ATmega328P which runs the show, with a DS3232MZ real-time clock onboard for keeping time. As you might imagine, creating such a large circular clock required a large PCB—roughly a square foot in size. It doesn’t come cheap, though [sjm4306] was lucky enough to have sponsorship to cover the build. [sjm4306] is still working on the firmware, and hopes to build a smaller, more compact version, which should cut costs compared to the large single board.

It’s a neat clock, and we’d know, having seen many a timepiece around these parts. Video after the break.

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DIY Your Own Red Light Therapy Gear

March 18, 2025 by Lewin Day 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” →

Some Useful Notes On The 6805-EC10 Addressable RGB LED

March 12, 2025 by Dave Rowntree 9 Comments

LEDs are getting smaller and smaller, and the newest generations of indexable RGB LEDs are even fiddlier to use than their already diminutive predecessors. [Alex Lorman] has written some notes about the minuscule SK6805-EC10 series of LEDs, which may be helpful to those wanting to learn how to deal with these in a more controlled manner.

Most hardware types will be very familiar with the 5050-sized devices, sold as Neopixels in some circles, which are so-named due to being physically 5.0 mm x 5.0 mm in the horizontal dimensions. Many LEDs are specified by this simple width by depth manner. As for addressable RGB LEDs (although not all addressable LEDs are RGB, there are many weird and wonderful combinations out there!) the next most common standard size down the scale is the 2020, also known as the ‘Dotstar.’ These are small enough to present a real soldering challenge, and getting a good placement result needs some real skills.

[Alex] wanted to use the even smaller EC10 or 1111 devices, which measure a staggering 1.1 mm x 1.1 mm! Adafruit’s product page mentions that these are not intended for hand soldering, but we bet you want to try! Anyway, [Alex] has created a KiCAD footprint and a handy test PCB for characterizing and getting used to handling these little suckers, which may help someone on their way. They note that hot air reflow soldering needs low temperature paste (this scribe recommends using MG Chemicals branded T3 Sn₄₂Bi₅₇Ag₁ paste in this application) and a very low heat to avoid cracking the cases open. Also, a low air flow rate to prevent blowing them all over the desk would also be smart. Perhaps these are more suited to hot plate or a proper convection oven?

As a bonus, [Alex] has previously worked with the slightly larger SK6805-1515 device, with some good extra notes around an interesting nonlinearity effect and the required gamma correction to get good colour perception. We’ll leave that to you readers to dig into. Happy soldering!

We’ve not yet seen many projects using these 1111 LEDs, but here’s one we dug up using the larger 1515 unit.

Ptychography For High Resolution Microscopy

March 5, 2025 by Al Williams 7 Comments

Nowadays, if you have a microscope, you probably have a camera of some sort attached. [Applied Science] shows how you can add an array of tiny LEDs and some compute power to produce high-resolution images — higher than you can get with the microscope on its own. The idea is to illuminate each LED in the array individually and take a picture. Then, an algorithm constructs a higher-resolution image from the collected images. You can see the results and an explanation in the video below.

You’d think you could use this to enhance a cheap microscope, but the truth is you need a high-quality microscope to start with. In addition, color cameras may not be usable, so you may have to find or create a monochrome camera.

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To Test A (Smart) LED

February 24, 2025 by Al Williams 14 Comments

Adding LEDs to a project used to be enough to make it cool. But these days, you need arrays of addressable multi-color LEDs, and that typically means WS2812B or something similar. The problem is that while it was pretty easy to test garden-variety LEDs, these devices can be a bit harder to troubleshoot. [Gokux] has the answer, as you can see in the video below.

Testing these was especially important to [Gokux] because they usually swipe the modules from other modules or LED strips. The little fixture sends the correct pulses to push the LED through several colors when you hold it down to the pads.

However, what if the LED is blinking but not totally right? How can you tell? Easy, there’s a reference LED that changes colors in sync with the device under test. So, if the LEDs match, you have a winner. If not… well, it’s time to desolder another donor LED.

This is one of those projects that you probably should have thought of, but also probably didn’t. While the tester here uses a Xiao microcontroller, any processor that can drive the LEDs would be easy to use. We’d be tempted to breadboard the tester, but you’d need a way to make contact with the LED. Maybe some foil tape would do the trick. Or pogo pins.

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Add A Little WOPR To Your Server Rack

February 19, 2025 by Tom Nardi 29 Comments

Like so many of us, [aforsberg] found themselves fascinated with the WOPR computer from WarGames — something about all those blinking LEDs must speak to nerds on some subconscious level. But rather than admire the light show from afar, they decided to recreate it at a scale suitable for a 1U server rack.

So what goes into this WOPR display? In this case, the recipe simply calls for three MAX7219 dot matrix LED modules and a Raspberry Pi Pico, although you could swap that out for your favorite microcontroller if you wish. You should probably stick with something that at least runs MicroPython though, or else you won’t be able to use the included Python code to mimic the light patterns seen in the film.

What we like most about this project is how simple and inexpensive it is to recreate. There’s no custom PCB, and all the parts are mass produced enough that the economies of scale have made them comically cheap. Even at Amazon prices, you’re looking at around $50 USD in parts, and quite a bit less if you’ve got the patience to order everything through AliExpress.

Critics will note that, in its current state, this display just shows gibberish (admittedly stylish gibberish, but still). But as we’ve seen with similar projects, that’s simply a matter of software.