LED Hacks

1870 Articles

Tidy LED Matrix Displays GIFs On Demand

May 30, 2025 by 4 Comments

When it comes to LED matrixes, building one is just the first step. Then you have to decide what to display on it. [panjanek] came up with a relatively flexible answer to this question, building an RGB LED matrix that can display the GIFs of your choice.

The web interface accepts GIFs for display.

[panjanek] grabbed WS2812B addressable LEDs for this project, assembling them into a 32 x 32 matrix that fits perfectly inside an off-the-shelf Ikea picture frame. The matrix is hooked up to an ESP8266 microcontroller, which acts as the brains of the operation. The WiFi-enabled microcontroller hosts its own web interface, with which the project can be controlled. Upon opening the page, it’s possible to upload a GIF file that will be displayed as an animation on the matrix itself. It’s also possible to stream UDP packets of bitmap data to the device to send real-time animations over a network.

It’s a neat build, and one that answers any questions of what you might display on your LED matrix when you’re finished assembling it. Code is on Github if you fancy implementing the GIF features in your own work. We’ve featured some unexpected LED matrix builds of late, like this innovative device for the M.2 slot. Meanwhile, if you’re cooking up your own creative LED builds, don’t hesitate to let us know on the tipsline!

A Simple Tip For Gluing Those LED Filaments

May 29, 2025 by 6 Comments

[Boylei] shows that those little LED filament strips make great freeze-frame blaster shots in a space battle diorama. That’s neat and all, but what we really want to highlight is a simple tip [Boylei] shares about working with these filament strips: how to glue them.

Glue doesn’t stick to LED filament strips, so put on a small piece of heat-shrink and glue to that instead.

The silicone (or silicone-like) coating on these LED filament strips means glue simply doesn’t stick. To work around this, [Boylei] puts a piece of clear heat shrink around the filament, and glues to that instead. If you want a visual, you can see him demonstrate at 6:11. It’s a simple and effective tip that’s certainly worth keeping in mind, especially since filament strips invite so many project ideas.

When LED filament strips first hit the hobbyist market they were attractive, but required high operating voltages. Nowadays they are not only cheaper, but work at battery-level voltages and come in a variety of colors.

These filaments have only gotten easier to work with over the years. Just remember to be gentle about bending them, and as [Boylei] demonstrates, a little piece of clear shrink tubing is all it takes to provide a versatile glue anchor. So if you had a project idea involving them that didn’t quite work out in the past, maybe it’s time to give it another go?

Continue reading “A Simple Tip For Gluing Those LED Filaments” →

LED Matrix Built For M.2 Interface

May 24, 2025 by 8 Comments

The M.2 slot is usually used for solid-state storage devices. However, [bitluni] had another fun idea for how to use the interface. He built an M.2 compatible LED matrix that adds a little light to your motherboard.

[bitluni] built a web tool for sending images to the matrix.
[bitluni] noted that the M.2 interface is remarkably flexible, able to offer everything from SATA connections to USB, PCI Express, and more. For this project, he elected to rely on PCI Express communication, using a WCH CH382 chip to translate from that interface to regular old serial communication.

He then hooked up the serial interface to a CH32V208 microcontroller, which was tasked with driving a 12×20 monochrome LED matrix. Even better, he was even able to set the microcontroller up to make it programmable upon first plugging it into a machine, thanks to its bootloader supporting serial programming out of the box. Some teething issues required rework and modification, but soon enough, [bitluni] had the LEDs blinking with the best of them. He then built a web-based drawing tool that could send artwork over serial direct to the matrix.

While most of us are using our M.2 slots for more traditional devices, it’s neat to see this build leverage them for another use. We could imagine displays like this becoming a neat little add-on to a blingy computer build for those with a slot or two to spare. Meanwhile, if you want to learn more about M.2, we’ve dived into the topic before.

Continue reading “LED Matrix Built For M.2 Interface” →

POV On The Flipper Zero

May 23, 2025 by 6 Comments

The Flipper Zero can do all kinds of neat stuff, like helping you cut keys or decode various radio transmissions. However, until now, it hasn’t been particularly adept at persistence of vision tasks. The LightMessenger was designed for that very purpose, and [Derek] recently wrote up a deep-dive into the interesting gadget.

The device doing its job.

The LightMessenger is a hardware add-on module developed by LAB401 in collaboration with [TIX LE GEEK] for the Flipper Zero. In persistence-of-vision mode, you can plug it in via the GPIO header and display messages in the air by shaking it around. Even better, you can do so in color, with a height resolution of 16 pixels—meaning you can display some nice text or basic graphics. You can key in different text or select and edit bitmaps using the utility on the Flipper screen itself. There’s even a simple flashlight mode, because why not?

In the second part of [Derek]’s write-up, he also goes into detail on the development and manufacturing process for the device.

Files are on GitHub for the curious. We’ve gone over the basics of POV projects before, too.

Continue reading “POV On The Flipper Zero” →

A man aims the LED flashlight into the night sky.

The World’s Longest Range LED Flashlight

May 13, 2025 by 39 Comments

[ApprehensiveHawk6178] reports that they have made the world’s longest range LED flashlight! While technically “handheld”, you’re gonna need both hands for this monster. According to the creator, it draws 1.2 kW (20 A @ 60 V) to deliver 100,000 lumens and approximately 20,000,000 candelas.

This spotlight is made from 48 white LEDs, wired in 16S3P configuration, and is powered by a similarly beefy 20S2P battery pack. That 1.2 kW power draw generates a lot of heat which is dissipated with an array of heat sinks and five cooling fans. Total cost was in the order of $2,000 USD.

It can be controlled via Bluetooth, and can run from its batteries for 30 minutes at full power. If you’d like to geek out over the specs click-through and read the discussion, a lot of technical detail is given and there are a bunch of photos showing the internals and assembly.

We’ve seen high-output LED lights with water cooling in the past, and wonder if that might be the next step for this particular build.

Thanks to [kms] for the tip.

A Delay Line Memory Demo Board

May 4, 2025 by 9 Comments

Delay line memory is a technology from yesteryear, but it’s not been entirely forgotten. [P-Lab] has developed a demo board for delay-line memory, which shows how it worked in a very obvious way with lots of visual aids.

If you’re unfamiliar with the technology, it’s a form of memory that was used in classic computers like the Univac-I and the Olivetti Programma 101. It’s a sequential-access technology, where data is stored as pulses in some kind of medium, and read out in order. Different forms of the technology exist, such as using acoustic pulses in mercury or torsional waves passing through coiled nickel wire.

In this case, [P-Lab] built a solid state delay line using TTL ICs, capable of storing a full 64 bits of information and running at speeds of up to 150 kHz. It also features a write-queuing system to ensure bits are written at the exact correct time — the sequential-access nature of the technology means random writes and reads aren’t actually possible. The really cool thing is that [P-Lab] paired the memory with lots of LEDs to show how it works. There are lights to indicate the operation of the clock, and the read and write cycles, as well as individual LEDs indicating the status of each individual bit as they roll around the delay line. Combined with the hexadecimal readouts, it makes it easy to get to grips with this old-school way of doing things.

We’ve seen previous work from[P-Lab] in this regard using old-school core rope memory, too. Continue reading “A Delay Line Memory Demo Board” →

RP2040 Spins Right ‘Round Inside POV Display

April 25, 2025 by 3 Comments

Sometimes, a flat display just won’t cut it. If you’re looking for something a little rounder, perhaps your vision could persist in in looking at [lhm0]’s rotating LED sphere RP2040 POV display.

As you might have guessed from that title, this persistence-of-vision display uses an RP2040 microcontroller as its beating (or spinning, rather) heart. An optional ESP01 provides a web interface for control. Since the whole assembly is rotating at high RPM, rather than slot in dev boards (like Pi Pico) as is often seen, [lhm0] has made custom PCBs to hold the actual SMD chips. Power is wireless, because who wants to deal with slip rings when they do not have to?

The LED-bending jig is a neat hack-within-a-hack.

[lhm0] has also bucked the current trend for individually-addressable LEDs, opting instead to address individual through-hole RGB LEDs via a 24-bit shift-register. Through the clever use of interlacing, those 64 LEDs produce a 128 line display. [lhm0] designed and printed an LED-bending jig to aid mounting the through-hole LEDs to the board at a perfect 90 degree angle.

What really takes this project the extra mile is that [lhm0] has also produced a custom binary video/image format for his display, .rs64, to encode images and video at the 128×256 format his sphere displays. That’s on github,while a seperate library hosts the firmware and KiCad files for the display itself.

This is hardly the first POV display we’ve highlighted, though admittedly it isn’t the cheapest one. There are even other spherical displays, but none of them seem to have gone to the trouble of creating a file format.

If you want to see it in action and watch construction, the video is embedded below.

Continue reading “RP2040 Spins Right ‘Round Inside POV Display” →