Tis The Season

December 7, 2024 by Elliot Williams 16 Comments

’Tis the season for soldering! At least at my house. My son and I made some fairly LED-laden gifts for the immediate relatives last year, and he’s got the blinky bug. We were brainstorming what we could make this year, and his response was “I don’t care, but it needs to have lots of LEDs”.

It’s also the season for reverse engineering, apparently, because we’re using a string of WS2812-alike “fairy lights”. These are actually really neat, they look good and are relatively cheap. It’s a string of RGB LEDs with drivers, each dipped in epoxy, and run on a common three-enameled-wire bus. Unlike WS2812s, which pass the data on to the next unit in the line and then display them with a latching pulse at the end of a sequence, these LED drivers seem to count how many RGB packets have been sent down the wire, and only respond to their own number.

This means that if you cut up a string of 200 LEDs, it behaves like a string of 200 WS2812s. But if you cut say 10 LEDs off the string, where you cut them matters. If you cut it off the front of the string, you only have to send 10 color packets. If you cut them off the other end, you need to send 290 dummy packets before they even start listening. Bizarre, but ’tis the season for bizarre hacks.

And finally, ’tis the season for first steps into “software architecture”. Which is to say that my son is appreciating functions for the first time in his life. Controlling one LED is easy, but making a light show is about two more abstraction layers on top of that. We’ve been having fun making them dim, twinkle, and chase so far. We only have two more weekends, though, and we don’t have a final light show figured out yet, but after all, ’tis the season for last minute present hacking.

Modular Magnetic LED Matrix

October 15, 2024 by Danie Conradie 5 Comments

[bitluni] seems rather fond of soldering lots of LEDs, and fortunately for us the result is always interesting eye candy. The latest iteration of this venture features 8 mm WS2812D-F8 addressable LEDs, offering a significant simplification in electronics and the potential for much brighter displays.

The previous version used off-the-shelf 8×8 LED panels but had to be multiplexed, limiting brightness, and required a more complex driver circuit. To control the panel, [bitluni] used the ATtiny running the MegaTinyCore Arduino core. Off-the-shelf four-pin magnetic connectors allow the panels to snap together. They work well but are comically difficult to solder since they keep grabbing the soldering iron. [bitluni] also created a simple battery module and 3D printed neat enclosures for everything.

Having faced the arduous task of fixing individual LEDs on massive LED walls in the past, [bitluni] experimented with staggered holes that allow through-hole LEDs to be plugged in without soldering. Unfortunately, with long leads protruding from the back of the PCB, shorting became an immediate issue. While he ultimately resorted to soldering them for reliability, we’re intrigued by the potential of refining this pluggable design.

The final product snapped together satisfyingly, and [bitluni] programmed a simple animation scheme that automatically updates as panels are added or removed. What would you use these for? Let us know in the comments below. Continue reading “Modular Magnetic LED Matrix” →

Build Yourself A Beautiful Interactive Light Toy

September 5, 2024 by Lewin Day 7 Comments

Sometimes, we build things with LEDs as indicator lamps or to illuminate something important. Sometimes, we build things with LEDs purely to glow and be beautiful. This interactive light toy from [Jens] falls into the latter category.

The build uses a 16×16 addressable LED matrix. [Jens] then ported some “Bouncy Bubbles” Processing code from Keith Peters to the Arduino Mega, and set it up to display on the matrix. An accelerometer was used to control the bouncing ball animations, while a second Arduino was then tapped to act as a musical synthesizer to add more vibes. The whole kit was then built into a 3D-printed housing with a nice hazy diffuser to give the LEDs a smoother, even look. [Jens] steps through how he got the diffuser just right, including a support structure that made all the difference to the aesthetic of the finished product. Getting diffusion right is key to making a nice LED project, and [Jens] got it very right here.

It’s a nice little art piece that looks kind of relaxing to play with in a dark room. We love a good glowable project here at Hackaday, so if you’ve built your own—don’t hesitate to let us know! Video after the break.

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The BAPPR Keeps Your Addressable LED System Cool

July 27, 2024 by Alexander Rowsell 17 Comments

We all love a nice strip or grid of addressable LEDs. It can add flair or an artistic touch to many projects, and it can make gaming computers look extra 1337. However, providing enough current to a long strip of addressable LEDs can sometimes be difficult. Often a separate voltage rail is needed to supply enough juice. At the same time, continually sending out data to animate them can often use 100% of the microcontroller’s CPU power, especially if the serial bus is being bit-banged. A crash or badly timed interrupt can leave the system in a weird state and sometimes with the LEDs not displaying the correct colours. Or you might just want to enter a power-saving mode from time to time on your main MCU? Well, the BAPPR is designed to address all of these problems.

[TheMariday] created the BAPPR and made it fully open-source. It’s a switch-mode power supply that can accept anywhere from 7 V to 17 V and converts it into a strong 5 V rail for typical addressable LEDs. It also has a “smart” mode where it monitors the data line going to the LEDs to see if there is activity. If for some reason the system stops sending data, the BAPPR can intervene and shut off the power to the LEDs, which can help prevent strange colour combinations from being displayed while the system recovers. Once data starts flowing again, power is restored and the light party can resume.

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LED Art Project Is Geometrically Beautiful

December 13, 2023 by Lewin Day 7 Comments

There is no shortage of companies on the Internet willing to sell you expensive glowing things to stick on your walls. Many hackers prefer to make their own however, and [Chris] is no exception. His LED wall art is neat, tidy, and stylish, all at once.

Wanting a geometric design, [Chris] decided to have his layout designed by a random number generator. He created his own tool that would generate a design using preset segment lengths arranged in a random fashion. Once he found a layout that worked for him, he designed a set of plastic adapters that would let him connect pre-cut lengths of aluminium channel together so he could assemble his design.

With the frame complete, he then laid the LED strips into the channels, after mapping out how he would connect the full circuit of addressable LED strips. He enlisted a Raspberry Pi Zero W as the brains of the operation, responsible for commanding the strips to light in the colors of his desire.

In a nice aesthetic touch, he sanded the whole frame and painted it a uniform grey color. This hid the joins between the 3D-printed parts and the aluminium channels, and gave it a more finished look. He also went to the trouble of graphing out the locations of the various LEDs in the frame, and used this data as the basis for animations that race between points on the frame. It’s somehow more compelling than the usual simple color fades and flashes of typical commercial products.

It’s a tidy build, and a level more artful than some of the off-the-shelf products out there. For his investment of time and money, [Chris] has netted an excellent piece of wall art in the process.

A Tiny Board For Driving LEDs In…Whatever

October 26, 2023 by Lewin Day 19 Comments

Whether you’re into chiptune or just playing Tetris on original hardware, you might like rocking a heavily-customized Game Boy. Lovely flashing LEDs can only improve the aesthetic, so if that’s what you’re after, you might consider the ARCCore board from [NatalieTheNerd].

The board is a compact and easy way to drive some addressable LEDs, with a form factor designed to take up a small amount of space when stuffed into a Game Boy or other game console. It rocks an RP2040 microcontroller set up to drive a strip of WS2812B LEDs. Three buttons are used to configure the color and brightness settings. The board is designed to run on 3.3 to 5 V, thanks to an onboard buck converter. It’s capable of delivering enough juice to run up to 10 RGB LEDs, though you could potentially use more if you ran them from external power.

You can use just about any microcontroller on the market today to run addressable LEDs if you so desire. If you want a compact drop-in solution that takes up less space, though, you might find the ARCCore useful. If you’ve got your own nifty kit for running addressable LEDs, don’t hesitate to share it with the broader hacker massive — hit the tipsline!

Minimalist LED Lamp Is Circular Beauty Incarnate

September 4, 2023 by Lewin Day 8 Comments

Lamps used to be things built to provide light with specific purpose, whether as reading lamps, desk lamps, or bedside table lamps. Now we just build them for the vibes, as with this minimalist LED lamp from [andrei.erdei].

The build uses a 3D-printed frame printed in opaque grey, with a diffuser element printed in a more translucent white. This is key to allowing the LED to nicely glow through the lamp without ugly distracting hotspots spoiling the effect. The lamp mounts 36 WS2812B LEDs in strip form. These are controlled from an Arduino Nano running the FastLED library for lightweight and easy control of the addressable LEDs. Smooth rainbow animations are made easy by the use of the HSV color space, which is more suitable for this job than the RGB color space you may otherwise be more familiar with.

[andrei.erdei] does a great job of explaining the build, including the assembly, electronics, and code aspects. The latter could serve as a particularly good resource if you’re just starting out on your own builds in the blinky, glowable space. Video after the break.

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