LED Hacks

1843 Articles

Is That A Tweet On Your Belt Buckle Or Are You Just Happy To See Me?

May 8, 2018 by 8 Comments

What a time to be alive! The range of things you never knew you needed but absolutely must have expands at a breakneck pace, such that it’s now possible to pick up a belt buckle with an embedded LED matrix to scroll messages. We have no idea what the use case for something like this is, but some people will buy anything.

One such person was a friend of [Brian Moreau], who doubled down after being gifted the glowing bauble by turning it into a WiFi enabled Tweet-scrolling belt buckle. It appears to be a just for fun project, and to be honest one would need a heck of a belt for the buckle after his mods. He added an ESP8266 to take care of monitoring his Twitter account and driving the display on the belt buckle, a non-trivial task given that the thing is programmed with only two buttons that scroll through characters to compose a message. The microcontroller might have fit inside the original buckle or only added a little to its bulk, but [Brian] decided to replace the two coin cells powering it with an external 6-volt battery pack. That required a buck converter to power the ESP, so the whole thing ended up being thrown in a case and acting more like a neat display than a flashy fashion statement.

We’d bet some tradeoffs could be made to reduce the bulk and get that buckle back where it belongs, though. Once it does, maybe it’ll be part of a complete LED-laden ensemble, from head to toe.

Glow In The Dark Globe On A Spherical Screen

May 6, 2018 by 18 Comments

Terrestrial globes are almost a thing of the past in an era of Google Earth, but they can still be an exciting object worth hacking together, as [Ivan Miranda] shows with his glow-in-the-dark globe. It’s a globe, it’s a display, and it’s a great use of glow in the dark filament.

For the mechanical part of this build, [Miranda] used glow in the dark filament to 3D print a sphere and a reinforcing ring that hides inside. A threaded rod through the middle secured with screws and bearings make an appropriate spindle, and is attached to a stepper motor in the 3D printed stand. So far, it’s a sphere made of glowey plastic. Where’s the ‘globe’ part coming from?

To project a globe onto this sphere, [Miranda] used a strip of WS2812B LEDs stuck to the inside of the stand’s arc are programmed to selectively illuminate the globe as it rotates on its axis. After a brief hiccup with getting the proper power supply, he was ready to test out his new….. giant light ball.

It turns out, the filament was a bit more transparent than he was expecting so he had to pull it all apart and cover the interior with aluminium tape. [Miranda] also took the chance to clean up the wiring, code, and upgrade to a Teensy 3.1 before another test.

Despite the resulting continental projection being upside-down, it worked! [Miranda] added a USB cable before he closed it up again in case he wanted to reprogram it and display any number of images down the line.

[Thanks for the tip, olivekrystal!]

Crawling A Dungeon, 64 Pixels At A Time

May 5, 2018 by 7 Comments

The trend in video games is toward not being able to differentiate them from live-action theatrical releases, and games studios are getting hard to tell from movie studios. But quality graphics don’t always translate into quality gameplay, and a lot can be accomplished with minimalist graphics. Turn the clock back a few decades and think about the quarters sucked up by classics like Pac-Man, Space Invaders, and even Pong if you have any doubts about that.

But even Pong had more than 64 pixels to work with, which is why this dungeon-crawler game on an 8×8 RGB matrix is so intriguing. You might think [Stolistic]’s game would be as simple as possible but think again. The video below shows it in action, and while new users will need a little help figuring out what the various colors mean, the game is remarkably engaging. The structure of the dungeon is random with multiple levels to unlock via the contents of power-up chests, and there are mobs to battle in a zoomed-in display. The game runs on an Arduino Uno and the matrix is driven by a bunch of 74HC595 shift registers.

It’s fun to see what can be accomplished with as little as possible. Looking for more low-res goodness? Check out this minimalist animated display, or a Geiger counter with a matrix display.

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Simple Home-built Projection Clock Projects Time

May 5, 2018 by 13 Comments

There are plenty of cheap projection clocks available, but as [Thomas Pototschnig] points out in this project, where’s the fun in just buying something? He set out to build a cheap projection clock using a small LCD screen, a cheap LED backlight, and a cheap lens. Cheap is the order of the day here, and [Thomas] succeeded admirably, creating a design that can be made with a couple of cheap PCBs, a 3D printer and the other parts mentioned above. He does a nice job of laying out his thinking in this design, showing how he calculated the projection path and made other decisions. His project has room to grow as well: it runs from an Arduino compatible STM32 that could handle many things other than showing the time if you were inclined to expand the project further.

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Giving An LED Bulb Some Smarts

May 5, 2018 by 54 Comments

How many of your projects been spawned purely out of bored daydreaming? For want of something more productive to do, [dantheflipman] hacked a standard LED bulb from Wal-Mart into a smart bulb.

After pulling it apart, they soldered wires to the threaded socket and added a connector for a Hi-Link hlk-pm01 power module. The output caps at 5 V and 600 mA, but who says this was going to be a searchlight? A Wemos D1 Mini clone slides nicely beside the power module, and stacked on top is a NeoPixel Jewel 7. [dantheflipman] admits he has yet to add a capacitor to ahead of the Jewel, so we’ll see how long the LEDs last. Crammed back together, the bulb is controlled via a prototype Blynk app. Good enough for a quick hack.

[dantheflipman] is upfront about messing with mains voltages: don’t do it unless you absolutely know what you’re doing. In this case, he has taken care with their soldering and epoxied all wire and solder joints to be sure nothing will come loose and short, and a ‘stress test’ is forthcoming.

Smart bulbs are cool no matter how you slice it, so a little more insight into how smart bulbs work with some of the nitty gritty that goes into hacking them might sate your thirst for knowledge.

[Via /r/arduino]

Build Your Own Black Hole

May 3, 2018 by 23 Comments

Okay, perhaps the title here is a bit of an exaggeration, but this black hole lamp made by [Will Donaldson] is an interesting approach to creating a black hole simulation without destroying the earth. This lamp uses a ring of LEDs surrounding a piece of black Lycra. A motor in the lamp base pulls the Lycra, representing the distorting effect that a singularity has on space-time. It also demonstrates how black holes can (in theory) evaporate by emitting radiation, a phenomenon called Hawking radiation. It’s a simple, but effective approach that physicists have used to demonstrate gravity for some time, using stretch fabric to simulate space-time and show how gravity warps it. It’s a two-dimensional version of a three (or more) dimensional phenomenon, but it works. And, hopefully, it won’t swallow the planet and destroy us all like the real thing might.

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Tron Inspired LED Desk Lighting

May 2, 2018 by 26 Comments

Reddit user [barbarisch] thought his computer desk was a bit boring, so he came up with a cool project to spice it up: A Tron-inspired computer desk with embedded LED strips!

[Barbarisch] took a basic desk and replaced the tops with ¾” oak plywood. The LED routes were planned out on the computer first and then marked out on the plywood. Using straightedges, [barbarisch] carefully used a router to create the straight grooves and then he created a jig for doing the circles. A bit of trimming and sanding and the three pieces of the desk match up.

After painting the desk, it was time to take a crack at the LEDs. Originally, [barbarisch] thought about 3D printing some diffusers to cover the individual WS2812B lights, but it wasn’t coming out to his liking, so diffusers have been put on the back-burner for now. Holes were drilled in the desk so that connections could be made between the different parts of the grooves and soldering was done between bits of the strips when turning corners. The whole thing’s being controlled by a Raspberry Pi and a Fadecandy USB controller for RGB strips. [Barbarisch] modified a Pi case so that the Fadecandy board would fit as well as printing out a bracket to mount the hardware under the desk.

A fun project to update that boring computer desk and to help you out, the python code which communicates with the Fadecandy server has been put up on GitHub. From the Reddit discussion, it looks like [barbarisch] might have found a solution for diffusing the LEDs! If it’s an LED desk you’re interested in, though, we’ve seen interactive LED tables and Mega LED desks before!

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