Building Festival Badges That Sync Themselves Up

May 20, 2026 by Zoe Skyforest No comments

Lots of music events these days hand out various glowing tchotchkes that flash and sync up with the performance. [Tony Goacher] has whipped up his own badges that can do just that, all without needing any sort of pairing or infrastructure to speak of.

The CrowdClock badges each feature a ring of 16 addressable RGB LEDs. Running the LEDs is an ESP32 microcontroller, which has lots of neat wireless capability baked in from the factory. [Tony] decided to leverage the ESP-NOW wireless communication protocol to enable each badge to broadcast its current local clock tick. Each device also listens out for clock ticks from other badges in the area, and updates its current clock tick value if it receives a higher one from another badge. This behaviour allows a bunch of badges within radio range to all sync up automatically in short order, and then run their LED sequences in sync. There’s no need for a master designation or anything, the devices just all sync to whichever badge has the highest clock value and go from there.

It’s a really neat way to create propagating self-syncing behaviour in distributed wireless nodes. Files are on Github for those curious to learn more. Meanwhile, if you’ve ever wondered how those concert wristbands work, we’ve looked at that too. Video after the break.

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Building A Working Replica Of The Chernobyl Power Plant’s SKALA Display

May 18, 2026 by Maya Posch 3 Comments

In a recent video by the [Chornobyl Family] it’s shown how they made the SKALA status display which was featured at the recent 40-year memorial exhibition of the Chornobyl Nuclear Power Plant (ChNPP) #4 reactor accident, along with the RBMK reactor control panel replica and SKALA console which they had made previously.

We previously covered this SKALA control system of the ChNPP’s RBMK reactors, as well as its 1990s modernization. This SKALA status display is one of the original elements of the control room, providing a status overview of the entire control system at a glance, including its processors and peripheral devices.

The replica uses similar looking components, with a metal casing and LED lighting that invokes the aesthetics of the original electroluminescent mnemonic panels. Overall the goal was to keep the appearance as close to the original as possible — they even had operators of the ChNPP reactors look over the panel and give it their stamp of approval.

Some of the components like the error indicators had to be 3D printed, while the metal case was cut out of sheet metal. There’s also a very big speaker for the alarm, at the top right of the panel. Along with the LEDs for the electroluminescent-style indicators this meant a lot of addressable LEDs and a lot of wiring.

The full build plans are available via the [Chornobyl Family] Patreon, if you feel like building up your own RBMK-style reactor control room.

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Mod This IKEA Lamp Into Smart Lighting For Not A Lot

May 15, 2026 by Donald Papp 13 Comments

The IKEA SKAFTSÄRV is an economical LED accent lamp, but while highly affordable it has only fixed lighting options. [simoneluconi] shows how it can easily be turned into a fully-configurable, WLED-connected, WiFi-enabled RGB lamp with little more than an ESP32-based board.

A thirty-LED lamp with integrated diffusor and stand can be had for surprisingly cheap. Add an equally-economical ESP32 board and it becomes a whole lot more.

To do this, the control board of the lamp gets replaced with an ESP32-C3 Super Mini board. Control and automation comes from WLED, open-source software that offers flexible automation and control for LED lights with a wide range of features, including native Android and iOS apps.

Modifying the SKAFTSÄRV lamp is fairly straightforward, but opening the unit does require breaking some glued seams to get inside. Once that’s done, the replacement board fits nicely into the housing and the unit can be closed back up. As far as WLED is concerned, the new lamp has 30 LEDs, WS281x type, GRB color order.

The end result is a stylish accent lamp with built-in diffusor and mount that can be controlled over WiFi with all the features WLED brings, such as easy integration with Home Assistant.

This isn’t the first time IKEA’s LED lighting has been given a powerup. Their pixel-style LED wall-mounted OBEGRÄNSAD, which displays a few canned animations out of the box, got considerably enhanced with a new controller.

Thanks [Crash] for the tip!

CRTs Are Too Mainstream, So Game On A Mechanical TV Instead

May 12, 2026 by Tyler August 18 Comments

Aside from nostalgia, people claim to like CRTs because they’re apprehendable– the technology just makes more sense than the arcane wibbly-wobbly solid-state madness going on inside the driver chip of your new OLED. CRTs weren’t the first technology used to display moving images though, and their mechanical forebears were even easier to understand. For that reason we suppose it was only a matter of time before one of The Youths– in this case a British YouTuber by the name of [smill]–tried gaming on a mechanical television display.

The game in question was Minecraft— because of course it was, that’s the new generation’s DOOM–and the mechanical TV in question is not a priceless 1920s antique but a commercial kit that reproduces [John Logie Baird]s 1925 televisor. If you’re not familiar, it uses a flat disk– called a Nipkow disk after its inventor– with a series of holes in a spiral to demodulate a single lamp’s brightness variations into monochrome image made of scan-lines. As you might imagine, the resolution depends both on the size of the disk and its speed, so with a tabletop example you’re not going to get much– in this case, 32 holes for 32 lines. At least they’re not interlaced this time.

Getting a video signal from the computer to the LED in the televisor kit was the hard part of the hack. Aside from actually playing on the diminutive monochrome display, that is. There is a “video2NBTV” tool that can do the job, as the Narrow Band TV signal used by amateur radio enthusiasts still has the compatible timing values and modulation as what the televisor kit uses. We suspect that’s because the Televisor people used the modern NBTV standard as a starting point for their electronics, since [Baird]’s device reportedly ran 30 lines at only 5 frames per second, compared to the 32 lines at 15 FPS here.

Some of you may turn your nose up at this as a mere YouTube stunt, which is fair enough. At the same time, we cannot wait for the eventual arms race. Imagine when someone decides to go for 4K cred? Staring through a supersonic Nipkow disk makes pointing a particle accelerator at your face downright mundane. The kit [smill] used was monochrome, but if you want to repeat his antics in glorious colour, you can 3D print your own TV.

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Let Twitch Chat Control Your LED Strings

May 2, 2026 by Zoe Skyforest 1 Comment

Once upon a time, someone set up a livestream wherein the messages from Twitch chat could control a game of Pokemon. Since then, we’ve seen Twitch control all sorts of things. If you’d like to have them play with some LEDs in your house, you might like this project from [pfeiffer3000].

The concept is simple enough. The heart of the build is an ESP32 microcontroller, which is easy to integrate with web services thanks to its onboard WiFi capability. It’s hooked upt o a string of WS2812B addressable RGB LEDs. The LEDs themselves are installed within table tennis balls to act as nice, spherical diffusers, and installed in a square frame made of PVC pipes. As for code, the rig uses the WLED library to drive the LED strings, and code from TwitchIO to interface with Twitch chat itself. It’s as simple as rigging up a bit of Python. With everything assembled, [pfeiffer3000] had an attractive LED grid that could be controlled directly by anyone watching their Twitch stream.

We’ve explored how to control things via Twitch before, too. It’s a fun way to add some interactivity to your livestream that really gets viewers involved. If you’ve been building your own audience-controlled projects, we’d love to hear about them on the tipsline!

Audio Reactive LED Strips Are Hard

April 14, 2026 by Jenny List 16 Comments

Back in 2017, Hackaday featured an audio reactive LED strip project from [Scott Lawson], that has over the years become an extremely popular choice for the party animals among us. We’re fascinated to read his retrospective analysis of the project, in which he looks at how it works in detail and explains that why for all its success, he’s still not satisfied with it.

Sound-to-light systems have been a staple of electronics for many decades, and have progressed from simple volume-based flashers and sequencers to complex DSP-driven affairs like his project. It’s particularly interesting to be reminded that the problem faced by the designer of such a system involves interfacing with human perception rather than making a pretty light show, and in that context it becomes more important to understand how humans perceive sound and light rather than to simply dump a visualization to the LEDs. We receive an introduction to some of the techniques used in speech recognition, because our brains are optimized to recognize activity in the speech frequency range, and in how humans register light intensity.

For all this sophistication and the impressive results it improves though, he’s not ready to call it complete. Making it work well with all musical genres is a challenge, as is that elusive human foot-tapping factor. He talks about using a neural network trained using accelerometer data from people listening to music, which can only be described as an exciting prospect. We genuinely look forward to seeing future versions of this project. Meanwhile if you’re curious, you can head back to 2017 and see our original coverage.

Bending Faux-Neon LEDs Make For Animations Glass Tubes Can’t Match

April 8, 2026 by Tyler August 10 Comments

Odds are, if you like neon lights, you’re not thrilled with the LED faux-“neon” strips that are supposed to replace them. They’ve got their advantages, but the light quality of RGB LEDs lacks something compared to the emission spectrum of nobel gas, at least to purists. On the other hand, you cannot create an animation by bending glass tubes, like [David Hamp-Gonsalves] has demonstrated with his Neon Animated Eye.

Back in the day, you’d have needed dozens of tubes for a flickery animation, but [David] figured that since these LED strips are flexible, why not flex them? He’s using addressable LEDs — WS2812s, specifically — so activating and deactivating the pupil of the eye is easy-peasy. Opening and closing the lid is accomplished with a geared motor driven by a TB6612 driver turning a barrel cam. The ends of the stiff LED strip being brought together and pulled apart result in the blinking effect here, but as [David] points out you’re hardly limited that specific motion. There’s a whole world of Tron-like glowing animatronics that can be created with this technique. Code and STLs are available on GitHub, though, if you want to replicate the eye exactly.

[David] says he’d like to see this in a storefront someday, but given that fatigue life is a thing, it might be something to keep in your back pocket for seasonal displays like Christmas and Halloween rather than something that’s going to run 24/7. On the other hand, if you’re careful about limiting flexion and which faux-neon strip you buy, you might be able to create an animation that can last for years.

This is hardly the first time we’ve seen these faux-neon strips , but it is the first time we’ve seen them animated. We can’t help but think the Hauntimator software we featured before would be a good paring with this hack.