Modular Magnetic LED Matrix

[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”

A chicken's egg with many holes glows beneath a glass globe set atop an inverted wooden bowl.

Glowing Egg Is A One-Oeuf Solution For Tracking Cycles

Look, if something happened to you every three weeks or so to basically turn you into a different person and factored heavily into whether any new humans were created, you’d probably want to keep abreast of the schedule, yeah? Yeah. So, while there are, of course, a ton of ways to do this with your phone, most of those apps do gross things with your data. Are you angry yet?

A standard chicken's egg with many holes both large and small.[Jakoba the Online Witch] certainly was, or if not angry, at least annoyed. So she built a glowing egg timer, which shines a different color based on current point in her cycle, to let her know when she is fertile and expecting Aunt Flo.

The coolest part is that this is an actual egg from one of [Jakoba]’s backyard chickens. No. The coolest part is how she was able to make so many holes without breaking it. (It took four tries.)

After bleaching the insides, the egg was ready to glow. As [Jakoba] says, the guts are simple — just a Wemos D1 Mini ESP8266, a WS2812 LED, and a heatsink. The enclosure consists of an inverted peanut bowl with a glass ornament hot-glued in place.

Once it was put together, all she had to do was add it in Home Assistant and use the current calendar state to trigger services from the YAML configuration.

Would you prefer an on-body solution? Here’s an earring that tracks temperature.

A small physical version of the game 2048, played with LEDs as numbers and tilt for input.

2024 Tiny Games Challenge: It’s 2048, But With LEDs

Remember the game 2048? You slide numbered tiles around on a grid, combining them until you have one tile with a value of 2048 (although it’s possible to go higher). Legend has it that 2048 was created by a bored teenager in the space of a weekend to see if he could program a game from scratch.

It only took a couple of weekends for [David] to get Tiny2048 up and running. In this version, each RGB value represents a number value, and input comes from a rudimentary gesture detector — tilt it this way and that to move the LEDs and combine the ‘numbers’. As you might imagine, it was a bit tricky to use colors to represent numbers, so each one had to be sufficiently unique.

[David] says that the LED matrix is a string of WS2812 LEDs in a grid formation, controlled by an ESP32-S3-MINI-1. Although this may be overkill, [David] broke out a bunch of IO at the top of the board so it can be used in the future as a dev board. Be sure to check it out in blinkenlight action after the break!

Continue reading “2024 Tiny Games Challenge: It’s 2048, But With LEDs”

It’s The Simple Things

I love minimal hacks. Limitations are sometimes the spark for our greatest creativity, and seeing someone do something truly marvelous with the simplest of technological ingredients never fails to put a smile on my face.

This week, it was the super-simple 1D Fireworks project by [Daniel Westhof]. Nothing more than an ESP8266 and a long RGB LED strip went into this effect on the hardware side, and indeed the code isn’t all that tricky either. But what it does is a very nice simulation of the physics that define the movement of a flare rocket and then all of the stars that explode out of it. And that makes it look so good.

Hackaday’s [Kristina Panos] is apparently also a fan of the single dimension, because she picked out some of my personal favorite uses of an LED strip, including Twang, to which we’ll admit we’re addicted, or any of the PONG versions.

But I’ve seen other games, including a button-mashing racer and various roller-coaster simulations. All with the same, essentially, two-part BOM. (OK, if you don’t count the buttons/accelerometer, or power supply.) Or this demo of sorting routines, or the Velocicoaster. And I think there’s more out there.

How much creativity can you pack into an LED strip? This sounds like we need to make a new contest…

1D Fireworks Are Nice And Quiet

Maybe you do it out of respect for the dogs and parents of young children in the neighborhood. Or maybe you do it because they’re harmful to the environment, or just because it’s too darn cold outside. Whatever your reasoning for not setting off fireworks, don’t fret — you can probably put together your own silent one-dimensional “fireworks” display from what you’ve got in the parts bin.

[Daniel Westhof]’s design is simple, requiring little more than a Wemos D1 Mini and a strip of WS2812 LEDs. Once activated, a red rocket shoots up from the ground and detonates, sending lights in both directions on the strip to imitate the bombs bursting in air. It’s controlled with a small push button switch, and there’s a deliciously large red LED indicator that shows the thing is ready for detonation.

You might be surprised to find that there’s a wide array of 1D gaming and animation projects out there, many of which made possible by the ubiquitous addressable RGB LED strip. We’ve seen a dungeon crawler, at least two different versions of the classic PONG, and even the makings of a simplified Wolfenstein.

Add Some Blinkenlights To Your Supercon Badge

We’re not sure what is more amazing here: the glow of the blinkenlights themselves, the tedium involved in creating it, or the fact that [makeTVee] soldered 280 microscopic WS2812 LEDs while at Supercon.

This hack began before the con when [makeTVee] designed the LED-diffusing frame in Fusion 360 and printed it in clear resin. Rather than solder the LEDs straight, the frame has 280 teeth that support each one at a 55° angle.

Not only does this look cool, it makes the bridging of DOUT to DIN much easier. That leaves GND and VCC to be painstakingly connected with 30 AWG wire. How, you might ask? With a little help from 3.5x magnifying glasses and the smallest soldering iron tip available, of course.

But that’s not all. Since 280 addressable LEDs need a lot of power, [makeTVee] also designed a holder for the LiPo battery pack that fits into the existing AA holders.

Want to see more awesome badge hacks? Check out the compendium.

How The WS2812 Is Made

[Scotty Allen] of Strange Parts is no stranger to Chinese factory tours, but this one is now our favorite. He visits the font of all WS2812s, World Semi, and takes a good look at the machines that make two million LEDs per day.

The big deal with the WS2812s, and all of the similar addressable LEDs that have followed them, is that they have a logic chip inside the LED that enables all the magic. And that means die-bonding bare-die ICs into each blinky. Watching all of the machines pick, place, glue, and melt bond wire is pretty awesome. Don’t miss the demo of the tape-and-frame. And would you believe that they test each smart LED before they kick it out the door? There’s a machine that clocks some data in and reads it back out the other side.

Do we take the addressable LED for granted today? Probably. But if you watch this video, maybe you’ll at least know what goes into making one, and the next time you’re blinking all over the place, you’ll spill a little for the epoxy-squirting machine. After all, the WS2812 is the LED that prompted us to ask, three years ago, if we could live without one.
Continue reading “How The WS2812 Is Made”