LED Hacks

1895 Articles

A Stylish Coffee Table Featuring Conway’s Game Of Life

March 10, 2020 by 11 Comments

Coffee tables are a great place to put your hot beverages, but most don’t offer a lot beyond that. For most people this is perfectly acceptable, but hackers often desire a little more. [Andrei Erdei] is one such person, who built Conway’s Game of Life into this handsome piece of furniture.

The build began with an existing coffee table, chosen for its glass top. Unfortunately, the top was painted black on one side, and was completely opaque, negating its use as a diffuser for LEDs. Instead, this was replaced with smoked glass, with frosted window film applied to make the final piece darker. This attention to detail allowed [Andrei] to install the WS2812B LED strips underneath such that they’re invisible when switched off. The LEDs themselves are run by a WEMOS D1 mini, based on the ESP8266. This microcontroller has plenty of grunt, which makes running the LEDs and the Game of Life code a cinch.

If you want to make something attractive and blinky, it’s hard to go wrong with Conway’s Game of Life. You can even use it to make a clock or a synthesizer; or build an entire game of Tetris within it. Video after the break.

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Lighting Up A Tiny Train Needs Tiny Tools

March 4, 2020 by 11 Comments

A tiny toy train that [voidnill] illuminated with a small LED strip fragment demonstrates several challenges that come with both modifying existing products, and working with small things in general. One is that it is hard in general to work around existing design choices and materials when modifying something. The second is that problems are magnified with everything is so small.

[voidnill]’s plentiful photos illustrate everything from drilling out small rivets and tapping the holes for screws to installing a tiny switch, LED strip, and button cells as a power supply. When things are so small, some of the usual solutions don’t apply. For example, cyanoacrylate glue may seem like a good idea for mounting small plastic parts, but CA glue easily wicks into components like the tiny power switch and gums up the insides, rendering it useless.

[voidnill] uses lots of careful cutting and patience to get everything done, and demonstrates the importance of quality tools. The LED strip fragment is driven by three small button cells, and while tape does a serviceable job as a battery holder, [voidnill] believes a 3D printed custom frame for the cells would really do the trick.

The kind of work that goes into making or modifying small things really puts into perspective the amount of effort behind projects like this coffee table with an N-gauge model railway inside it.

Using IR LEDs To Hide In Plain Sight

February 28, 2020 by 91 Comments

Getting by without falling under the gaze of surveillance cameras doesn’t seem possible nowadays – from malls to street corners, it’s getting more common for organizations to use surveillance cameras to keep patrons in check. While the freedom of assembly is considered a basic human right in documents such as the US Condition and the Universal Declaration of Human Rights, it is not a right that is respected everywhere in the world. Often times, governments enforcing order will identify individuals using image recognition programs, preventing them from assembling or demonstrating against their government.

Freedom Shield built by engineer [Nick Bild] is an attempt at breaking away from the status quo and giving people a choice on whether they want to be seen or not. The spectrum of radiation visible to humans maxes out around 740nm, allowing the IR waves to remain undetected by normal observers.

The project uses 940nm infrared (IR) LEDs embedded in clothes to overwhelm photo diodes in IR-sensitive cameras used for surveillance. Since the wavelength of the lights are not visible to humans, they don’t obstruct normal behavior, making it an ideal way to hide in plain sight. Of course, using SMD LEDs rather than the larger sizes would also help with making the lights even less visible to the naked eye.

The result doesn’t perfectly obscure your face from cameras, but for a proof-of-concept it’s certainly a example of how to avoid being tracked.

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Latest FlexLED Milestone Refines The POV Display

February 28, 2020 by 7 Comments

With his FlexLED project, [Carl Bugeja] is trying to perfect a simple and affordable persistence of vision (POV) display capable of generating “holographic” characters in mid-air. Traditionally POV systems spin LEDs rapidly to create the desired illusion, but that means motors, slip rings, and noise. As the name implies, the goal with this project is to do away with all that and replace it with a self-actuating flexible PCB.

The device is able to quickly move the LEDs back and forth quietly and efficiently thanks to a permanent magnet and magnetic coils integrated into the flexible PCB. With no motors or gears, the whole unit is smaller and less complex than other POV displays. As an added bonus, there’s no danger to the operator or the device should a curious user stick their finger into it.

The last time we took a look at this project, [Carl] had entered an earlier single-LED version into the 2019 Hackaday Prize. Competition was tough last year, and unfortunately FlexLED didn’t get selected as a Finalist. But we’re still extremely interested in seeing the project develop, and we imagine so are you.

The recently completed second version of the display features an improved coil design, eight RGB LEDs and a 3D printed base with integrated magnet. With more LEDs onboard, a single display is able to show multiple characters and even rudimentary animations. A large array of these flapping elements promises to be quite a sight.

But before you get too excited, [Carl] does have some bad news. For one, the cost of building them in small quantities is high, which is always tough for a single hacker trying to iterate a design. Worse, some of the LEDs seem to have died on this prototype already. He says it likely has something to do with the stress of flexing back and forth so quickly, which is obviously a bit troubling. He’s looking to get some feedback from the community, and is hoping to address these issues in the next version.

For an interesting look into his flexible PCB actuator projects, check out the interview [Carl] did with us at the 2018 Hackaday Superconference.

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Gravity-Defying Water Droplet Fountain Gets An Upgrade

February 25, 2020 by 2 Comments

When we last saw [isaac879]’s levitating RGB time fountain, it was made of wood which meant that it would absorb water and didn’t really show off the effect very well. His new version solves this problem with an acrylic case, new PCB and an updated circuit.

Like the original, this project drops water past strobing RGB LEDs creating an illusion of levitating, undulating colored water droplets. The pump at the top creates the droplets, but the timing has a tendency to drift over time. He thus implemented a PID controller to manage the pump’s drip rate, which was done by having the droplets pass by an infrared diode connected to an ATTiny85. The ’85 used the diode and PWM to control the pump motor speed and communicated to the Arduino over I2C.

The video shown below shows the whole process of designing and building the new time fountain. Everything from circuit and PCB design to 3D printing to assembly is shown along with narration describing what’s going on in case you want to build one yourself. If you do, all the files and components required are listed in the info section of the video.

There’s more that [isaac879] wants to do to improve the time fountain, but V2 looks great. It’s sleeker and smaller than the original and solves some of the design issues of the first. For more inspiration, check out some of the other levitating water fountain projects that have been posted over the years.

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Levitating Starship Model Comes In For A Landing

February 25, 2020 by 9 Comments

If everything goes according to plan, Elon Musk says the first generation of SpaceX’s massive Starship will make an orbital flight before the end of 2020. That’s a pretty bold claim, but when you’ve made landing rockets on their tails as in the old science fiction pulp magazines seem routine, we suppose you’ve earned the right to a bit of bravado. We’re excited to see the vehicle evolve over the next several months, but even if the real one stays grounded, we’ll gladly take this “flying” Starship model from [Chris Chimienti] as a consolation prize.

A magnetic levitation module, we’re officially in the future.

Feeling a bit let down by the 3D printable models of the Starship he found online, [Chris] set out to build his own. But it wasn’t enough to just make his bigger, stronger, and more accurate to Starship’s current design; he also wanted to make it a bit more exciting. Some RGB LEDs an Arduino embedded in the “cloud” stand the rocket sits on was a good start, and the landing pad inspired by SpaceX’s real autonomous spaceport drone ship Just Read the Instructions looks great all lit up.

But this is Starship we’re talking about, a vehicle that could literally push humanity towards being a multi-planet species. To do it justice, you’ve really got to knock it out of the park. So [Chris] found a magnetic levitation module online that could support a few hundred grams, and set to work on making his plastic Starship actually hover over the landing pad.

As you might imagine, it was a bit tricky. The first versions of the rocket looked great but came out too heavy, so he switched over to printing the model in so-called “spiral vase mode” which made it entirely hollow. Now far lighter and with a magnetic plate fit into the bottom, it was stable enough to float on its own. For the final touch, [Chris] added some red LEDs and a coin cell battery to the base of the Starship so it looks like the sleek craft is performing a last-second landing burn with its “impossible” full-flow staged combustion engines.

This isn’t the first time we’ve seen a model rocket with an electronic glowing cloud under it, but it’s certainly the first one we’ve seen that could levitate in mid-air. While this little rocket might not make it all the way to Mars, we wouldn’t be surprised to see it touching down on the desks of other hackers and makers in the near future.

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We Ruined Status LEDs; Here’s Why That Needs To Change

February 20, 2020 by 259 Comments

Ah, the humble status LED. Just about every piece of home electronics, every circuit module, and anything else that draws current seems to have one. In the days of yore, a humble indicator gave a subtle glow from behind a panel, and this was fine. Then the 1990s happened, and everything got much much worse.

It’s Not The Technology, It’s How You Use It

With great brightness, comes great responsibility.

The 1990s brought us much good: Nirvana, Linux, and of course the blue LED. Much like “Teen Spirit”, the latter quickly fell into overuse: the technology rapidly became the sigil of all that was new and great, much to the ocular pain of the buying public.

This decision ranks up there for stupidity with other such questionable choices as hiring a rental car at the airport, or invading Russia in the winter. A status LED, most would agree, is there to indicate status. It need only deliver enough light to be seen when observed by a querying eye. What it need not do is glow with the intensity of a dying star, or illuminate an entire room for that matter. But, in the desperate attempts of product designers to appear on the cutting edge, the new, brighter LED triumphed over all in these applications. Continue reading “We Ruined Status LEDs; Here’s Why That Needs To Change” →