LED Hacks

1822 Articles

A Guide For Driving LED Matrices

November 27, 2018 by 8 Comments

Building an LED matrix is a fun project, but it can be a bit of a pain. Usually it starts with hand-soldering individual LEDs and resistors together, then hooking them up to rows and columns so they can be driven by a microcontroller of some sort. That’s a lot of tedious work, but you can order an LED matrix pre-built to save some time and headache. You’ll still need a driver though, and while building one yourself can be rewarding there are many pitfalls and trade-offs to consider when undertaking that project as well. Or, you can consider one of a number of drivers that [deshipu] has outlined in detail.

The hangups surrounding the driver board generally revolve around the issue of getting constant brightness from LEDs regardless of how many in the row or column are illuminated at one time. Since they are typically driven one row or column at a time, the more that are on the lower the brightness each LED will have. Driver boards take different approaches to solving this problem, which usually involve a combination of high-speed scanning of the matrix or using a constant-current source in order to eliminate the need for resistors. [deshipu] outlines four popular chips that achieve these purposes, and he highlights their pros and cons to help anyone looking to build something like this.

Most of these boards will get you to an 8×8 LED matrix with no problem, with a few going a few pixels higher in either direction. That might be enough for most of our needs, but for something larger you’ll need other solutions like the one found in this 64×32 LED matrix clock. There are also even more complicated drivers if you go into extra dimensions.

Photo credit: Komatta [Public domain], from Wikimedia Commons

LED-ifying A Guitar, Part Two

November 23, 2018 by 10 Comments

An electric guitar is all about stage presence. Need to be cooler than a single guitar? No problem — there are double neck guitars. Need to be cooler than that? No problem, the guy from Cheap Trick has a five-neck guitar. Need to be cooler than that? Robbie Robertson played a guitar with an extra mandolin neck on The Last Waltz. Where do you go from there? Obviously, the solution is putting a TV in your guitar with a boatload of individually addressable LEDs in a guitar. That’s what [Englandsaurus] is doing, and the build thread is now getting into how to turn a bunch of LEDs into a display.

In the first installment of this build thread, [Englandsaurus] went over the construction of the guitar itself and how a hundred individually addressable RGB LEDs were installed inside two pieces of plexiglass. When the guitar is displaying white at full brightness, the power draw is 500 W. This, in itself, is remarkable; no sane person would ever plug a guitar into a 500 W amp, and even 100 Watts is just too damn loud. There’s more power going to the lights here than the amplifier, and that’s awesome.

Simply sticking LEDs in a guitar does not a build log make, so how are these pixels addressed? How do you make a display out of a bunch of LEDs? This is a hell of a problem, but with Artnet and Resolume Arena 6 these pixels can be mapped into a cartesian grid, and from there it’s just putting video on the guitar.

While the first installment of this build is great and shows you how far you can take electronics in a guitar, this installment is a great demo of turning a bunch of LEDs into a display, something that applies to more than just a gigantic glowey guitar.

Disco Ain’t Dead: Blinky Ball Makes You Solder Inside A Dome

November 22, 2018 by 10 Comments

Disco balls take a zillion mirrors glued to a sphere and shine a spotlight on them. But what if the ball itself was the light source? Here’s a modern version that uses addressable LEDs in a 3D-printed sphere that also hides the electronics inside the ball itself.

Check out the video below to see the fantastic results. It’s a Teensy 3.6 driving a whopping 130 WS2812 LEDs to make this happen. (Even though the sphere has the lowest surface area to volume ratio.) There’s even a microphone and an accelerometer to make the orb interactive. Hidden inside is a 4400 mAh battery pack that handles recharging and feeds 5 V to the project.

For us, it’s the fabrication that really makes this even more impressive. The sphere itself is 3D printed as four rings that combine to form a sphere. This makes perfect spacing for the LEDs a snap, but you’re going to spend some time soldering the voltage, ground, and data connections from pixel to pixel. In this case that’s greatly simplified because the LEDs were sourced from AliExpress already hosted on a little circle of PCB so you’re not trying to solder on the component itself. Still, that’s something like 390 wires requiring 780 solder joints!

We love seeing an LED ball you can hold in your hand. But if you do want something bigger, try this 540 LED sphere built from triangular PCBs.

Continue reading “Disco Ain’t Dead: Blinky Ball Makes You Solder Inside A Dome” →

Beautiful Moving Origami Light Made From Scrap

November 22, 2018 by 3 Comments

Whenever [MakerMan] hits our tip line with one of his creations, we know it’s going to be something special. His projects are almost exclusively built using scrap and salvaged components, and really serve as a reminder of what’s possible if you’re willing to open your mind a bit. Whether done out of thrift or necessity, he proves the old adage that one man’s trash is often another’s treasure.

We’ve come to expect mainly practical builds from [MakerMan], so the beautiful ceiling light which he refers to as a “Kinetic Chandelier”, is something of a change of pace. The computer controlled light is able to fold itself up like an umbrella while delivering a pleasing diffuse LED glow. He tells us it’s a prototype he’s building on commission for a client, and we’re going to go out on a limb and say he’s going to have a very satisfied customer with this one.

Like all of his builds, the Kinetic Chandelier is almost entirely built out of repurposed components. The support rods are rusty and bent when he found them, but after cutting them down to size and hitting them with a coat of spray paint you’d never suspect they weren’t purpose-made. The light’s “hub” is cut out of a chunk of steel with an angle grinder, and uses bits of bike chain for a flexible linkage.

Perhaps most impressive is his DIY capstan which is used to raise and lower the center of the light. [MakerMan] turns down an aluminum pulley on a lathe to fit the beefy gear motor, and then pairs that with a few idler pulleys held in place with bits of rebar welded together. It looks like something out of Mad Max, but it gets the job done.

Finally, he salvages the LED panels out of a couple of cheap work lights and welds up some more rebar to mount them to the capstan at the appropriate angle. This gives the light an impressive internal glow without a clear source when viewed from below, and really gives it an otherworldly appearance.

This isn’t the first time we’ve seen a hacker put together their own chandelier, or even the first time we’ve seen it done with scrap parts. But what [MakerMan] has put together here may well be the most objectively attractive one we’ve seen so far.

Continue reading “Beautiful Moving Origami Light Made From Scrap” →

Pringles Can Turned Vaporwave Lamp

November 8, 2018 by 4 Comments

We play host to a lot of incredibly complex projects here at Hackaday; take a look at some of the entries in the Hackaday Prize for some real world-class engineering. But the hacks you can knock out in an afternoon are often just as compelling as the flagship projects. After all, not everyone is looking to devote years of their lives into building some complex machine.

Case in point, this very slick lamp built by [mytzusky]. Made of nothing more exotic than an old Pringles can and an RGB LED strip, this is something that can potentially be built with what you have laying around right now. All you need to provide is a bit of geometry, a steady hand, and a love for anything that looks like it could pass as a prop in a TRON fan film.

The first step is getting the Pringles can: either find one in the trash or treat yourself to a stack of weird hard potato chip sorta things. Once you’ve got the can, you need to cut out your design. You could print out the template provided by [mytzusky] if you want, but you could put your own spin on it instead. Just remember that the design needs to make sense when you wrap it around the can.

With the lines cut out of the can, the whole thing gets wrapped with a few sheets of standard white paper. This will not only cover the original label but diffuse the light coming from the cuts you’ve just made. [Mytzusky] doesn’t mention it, but some kind of sealer applied to the paper might be a good idea if you’re looking to keep this thing around for the long haul.

Finally, an RGB LED strip goes inside the can. Make sure to flip the can upside down for this part, with the solid end on the top and the clear lid on the bottom. Not only does this let you run the wire out of the bottom, but provides a very cool ring of diffuse light at the bottom of the lamp.

This is another excellent example of an “upcycled” project which uses literal trash as a building material. It might take a little outside the box thinking, but the results can be very impressive.

Lightsaber Uses Pogo Pins To Make Assembly A Breeze

November 7, 2018 by 9 Comments

There was an endless supply of fantastic projects at Supercon this year, but one whose fit and finish really stood out was [Scott]’s lightsaber. If you were walking around and saw someone with a very bright RGB device with a chromed-out handle hanging off their belt it was probably this, though it may have been hard to look at directly. On the outside, the saber looks like a well-polished cosplay prop, and it is! But when Scott quickly broke down the device into component pieces it was apparent that extra care had been put into the assembly of the electronics.

Like any good lightsaber replica the blade is lit, and wow is it bright. The construction is fairly simple, it’s a triplet of WS2812B LED strips back to back on a triangular core, mounted inside a translucent polycarbonate tube with a diffuser. Not especially unusual. But the blade can be popped off the hilt at a moments notice for easy transport and storage, so the strips can’t be soldered in. Connectors would have worked, but who wants flying wires when they’re disconnecting their lightsaber blade. The answer? Pogo pins! Scott runs the power, ground, and data lines out of the strips and into a small board with slip ring-style plated rings. On the hilt, there is a matching array of pogo pins to pass along power and data. The data lines from all the strips are tied together minimizing the number of connections to make, and the outer two power rings have more than one pin for better current-carrying capacity. A handy side effect is that there is nowhere on the blade where there aren’t LEDs; the strips go down to the very end of the blade where it meets the main board inside the hilt.

The hilt is filled with an assembly of 18650’s and a Teensy mounted with a custom shield, all fit inside a printed midframe. The whole build is all about robust design that’s easy to assemble. The main board is book-ended by perpendicular PCBs mounted to the ends, one at the top to connect to the blade and one at the bottom to connect to a speaker. Towards the bottom there is space for an optional Bluetooth radio to allow remote RGB control.

Scott is selling this as a product but also provides detailed instructions and parts lists for each component. Assembly instructions for the blade are here. The hilt is here. And pogo adapters are on OSH Park here. An overview of the firmware with links to GitHub is here. Check out a walkthrough of the handle assembly and blade attachment after the break!

Continue reading “Lightsaber Uses Pogo Pins To Make Assembly A Breeze” →

Gyro Controlled RGB Blinky Ball Will Light Up Your Life

November 2, 2018 by 4 Comments

[James Bruton], from the XRobots YouTube channel is known for his multipart robot and cosplay builds. Occasionally, though, he creates a one-off build. Recently, he created a video showing how to build a LED ball that changes color depending on its movement.

The project is built around a series of 3D printed “arms” around a hollow core, each loaded with a strip of APA102 RGB LEDs. An Arduino Mega reads orientation data from an MPU6050 and changes the color of the LEDs based on that input. Two buttons attached to the Mega modify the way that the LEDs change color. The Mega, MPU6050, battery and power circuitry are mounted in the middle of the ball. The DotStar strips are stuck to the outside of the curved arms and the wiring goes from one end of the DotStar strip, up through the middle column of the ball to the top of the next arm. This means more complicated wiring but allows for easier programming of the LEDs.

Unlike [James’] other projects, this one is a quickie, but it works as a great introduction to programming DotStar LEDs with an Arduino, as well as using an accelerometer and gyro chip. The code and the CAD is up on Github if you want to create your own. [James] has had a few of his projects on the site before; check out his Open Dog project, but there’s also another blinky ball project as well.

Continue reading “Gyro Controlled RGB Blinky Ball Will Light Up Your Life” →