Addressable LED strings have made it easier than ever to build fun glowable projects with all kinds of exciting animations. However, if you’re not going with a simple grid layout, it can be a little difficult to map your strings out in code. Fear not, for [Jason Coon] has provided a tool to help out with just that!
[Jason]’s web app, accessible here. is used for mapping out irregular layouts when working with addressable LED strings like the WS2812B and others that work with libraries like FastLED and Pixelblaze. If you’re making some kind of LED globe, crazy LED tree, or other non-gridular shape, this tool can help.
The first step is to create a layout of your LEDs in a Google Sheets table, which can then be pasted into the web app. Then, the app handles generating the necessary code to address the LEDs in an order corresponding to the physical layout.
[Jason] does a great job of explaining how the tool works, and demonstrates it working with a bowtie-like serpentine layout with rainbow animations. The tool can even provide visual previews of the layout so you can verify what you’ve typed in makes sense.
When you’re building wearables and glowables, sometimes a flashy rainbow animation is all you need. [Geeky Faye] likes to go a little further, however, and built this impressive necklace that serves to inform on the local air quality.
The necklace consists of a series of Neopixel LED strips, housed within a tidy 3D printed housing made with flexible filament. A dovetail joint makes putting on and removing the necklace a cinch. A TinyPico V2, based on the ESP32, runs the show, as it’s very small and thus perfect for the wearable application. A USB power bank provides power to the microcontroller and LEDs.
The TinyPico uses its WiFi connection to query a server fed with air quality data from a separate sensor unit. The necklace displays a calm breathing animation as standard in cool tones. However, when air quality deteriorates, it shows warmer and hotter colors in a more pointed and vibrant fashion.
It’s a neat project that shows off [Geeky Faye]’s abilities at both electronics and tasteful wearable fabrication. It’s not always easy to build projects that are both functional and comfortable to wear, but this one works on both counts. Both the 3D files for the necklace and the microcontroller firmware code is included in the GitHub repo for those keen to dive in to the nitty gritty.
[Jeremy Cook] writes to us about a project of his – a bouquet of LED cube flowers. The flowers are PCB cubes made out of small castellated PCBs, each of those having an individually addressable LED in its center. Castellations hold the cubes together mechanically, and thanks to a cleverly chosen pinout, only two different kinds of PCB need to be ordered for building such a flower!
As a vase for these flowers, he decided to use a glass bottle – which would need a cutout to fit a ESP8266-powered NodeMCU board, a controller of choice for the project. After a few different approaches for cutting glass all resulted in the bottles cracking, he gave up on the “clean cut” idea and reused one of the broken bottles, gluing it back together well enough for the aesthetic to work.
[Jeremy] tells us that he’s had help from a hack we covered back in 2017 – using a diode for level shifting, as the ESP8266’s 3.3 V level signals aren’t a good match for WS2812 inputs. From there, the WLED firmware for the ESP8266 ties everything together beautifully. It’s clear that [Jeremy] had a field day designing this, toying with all the ideas and approaches!
As you might expect, the release of last year’s Ghostbusters: Afterlife has not only lead to renewed interest in the old 1980s toys and tie-in merchandise, but has spawned a whole new generation of blinking plastic gadgets to delight children of all ages. Of course, for folks like us, that means more hardware to hack on.
In a recent post to the official Ghostbusters YouTube channel, professional prop maker [Ben Eadie] shows off some of the tricks of the trade when he takes a $15 USD “PKE Meter” toy from Hasbro and turns it into a screen-quality prop. Even if you’re not looking to get an early start on your Halloween costume, the techniques demonstrated in this video could be easily adapted to other projects. For those whose next ideal home improvement is a fireman’s pole and an ectoplasmic laser-confinement grid, you might want to grab a couple of these toys while they’re still cheap for eventual conversion.
Uncovering the silver makes the piece look worn down.
The biggest takeaway from the video is probably the finishing techniques, as they could be used on any sort of realistic prop build. [Ben] starts by using a cabinet scraper to smooth out the lines on the plastic toy, and any holes are filled with the familiar baking soda and cyanoacrylate glue trick. Once the surfaces have been prepped, all the principle parts are sprayed with an adhesion promoter, followed by a coat of silver, and then the final black color.
This allows him to create a convincing “chipped paint” effect by strategically sanding or scraping through the top coat. Dabbing some toothpaste where you want the device to look worn down before spraying the final coat makes the process even faster, as it will prevent the top coat from sticking to the silver in the first place.
Unfortunately [Ben] doesn’t spend a whole lot of time explaining the electronics side of things, but it doesn’t look like there’s anything too complex going on. All the original gear is stripped, and it gets replaced with a microcontroller which we believe is an Adafruit ItsyBitsy nRF52840 Express. This is connected to two strings of tiny APA102 addressable LEDs which are run down the “wings” (we especially like the 3D printed lenses used to replace the original solid pips), and one that’s used to provide the iconic sine-wave display.
Everyone loves LED matrices, and even if you can’t find what you like commercially, it’s pretty easy to make just what you want. Need it big? No problem; just order a big PCB and some WS2812s. Need something tiny? There are ridiculously small LEDs that will test your SMD skills, as well as your vision.
But what if you want a small matrix that’s actually a big matrix in disguise? For that, you’ll want to follow [elliotmade]’s lead and incorporate fiber optics into your LED matrix. The build starts with a 16×16 matrix of WS2812B addressable LEDs, with fairly tight spacing but still 160 mm on a side. The flexible matrix was sandwiched between a metal backing plate and a plastic bezel with holes directly over each LED. Each hole accepts one end of a generous length of flexible 1.5-mm acrylic light pipe material; the other end plugs into a block of aluminum with a 35 by 7 matrix of similar holes. The small block is supported above the baseplate by standoffs, but it looks like the graceful bundle of fibers is holding up the smaller display.
A Raspberry Pi Pico running a CircutPython program does the job of controlling the LEDs, and as you can see in the video below, the effect is quite lovely. Just enough light leaks out from the fibers to make a fascinating show in the background while the small display does its thing. We’ve seen a few practical uses for such a thing, but we’re OK with this just being pretty. It does give one ideas about adding fiber optics to circuit sculptures, though.
Often, financial motivation results in people writing great educational material for hackers. Such is absolutely the case with this extensive documentation blog post on addressable LEDs by [DeRun]. This article could very be named “Addressable LEDs 101”, and it’s a must-scroll-through for anyone, whether you’re a seasoned hacker, or an artist with hardly any technical background and a desire to put LEDs in your creations.
This blog post is easy to read, painting a complete picture of what you can expect from different addressable LED types, and with apt illustrations to boot. Ever wonder which one of the addressable strips you should get from your retailer of choice, and what are the limitations of any specific type? Or, perhaps, you’d like to know – why is it that a strip with a certain LED controller is suspiciously cheap or expensive? You’re more than welcome to, at least, scroll through and fill into any of your addressable LED knowledge gaps, whether it’s voltage drops, color accuracy differences, data transfer protocol basics or dead LED failsafes.
Addressable LEDs have a special place in our hearts, it’s as if the sun started shining brighter after we’ve discovered them… or, perhaps, it’s all the LEDs we are now able to use. WS2812 is a staple of the addressable LED world, which is why we see them even be targets of both clone manufacturers and patent trolls. However, just like the blog post we highlight today mentions, there’s plenty of other options. Either way do keep coming cover a new addressable LED-related hack, like rewriting their drivers to optimize them, or adding 3.3V compatibility with just a diode.
The University of Pennsylvania has a team that did a little light research. Well, not light in the usual sense of that phrase. They used very strong light to levitate Mylar disks in a vacuum chamber.
Of course, it is no secret that light can exert pressure. That’s how solar sails work and some scientists have used it to work with aerosols and the like. But this appears to be the first time light lifted a large item against gravity. The team claims that their tests showed that a sunlight-powered flying vehicle might carry up to ten milligrams of payload. That doesn’t sound like much, but it’s impressive and the paper mentions that since the lift is not from aerodynamic forces, there might be applications in flying at very high altitudes.
The Mylar disks were 500 nanometers thick and had a 300 nanometer layer of carbon nanotubes beneath. The nanotubes absorb light, make the disks more rigid, and improve the Mylar’s surface-gas characteristics. The light source had a strong center beam and an even stronger ring around the center beam that causes the disk to remain over the center beam. The LED system used eight arrays, each consuming 100 watts of input power.
