Hackaday Editors Mike Szczys and Elliot Williams get caught up on the most interesting hacks of the past week. On this episode we take a deep dive into radiation-monitor projects, both Geiger tube and scintillator based, as well as LED cube projects that pack pixels onto six PCBs with parts counts reaching into the tens of thousands. In the 3D printing world we want non-planar printing to be the next big thing. Padauk microcontrollers are small, cheap, and do things in really interesting ways if you don’t mind embracing the ecosystem. And what’s the best way to read a water meter with a microcontroller?
Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!
When [Freddie] was faced with the challenge of building a sendoff gift for an an LED-loving coworker he hatched a plan. Instead of making a display from existing video wall LED panels he would make a cube. But not just any cube, a miniature desk sized one that wasn’t short of features or performance. We’d be over the moon if someone gifted us with this itty-bitty Qi coil-powered masterpiece of an RGB cube.
Recently we’ve been blessed with a bevy of beautiful, animatedRGBcubes but none hit quite this intersection of size and function. The key ingredient here is tiny but affordable RGB LEDs which measure 1 mm on a side. But LEDs this small are dwarfed by the otherwise minuscule “2020” package WS2812’s and APA102s of the world. Pushing his layout capabilities to the max [Freddie] squeezed each package together into a grid with elements separated by less than 1 mm, resulting in a 64 LED panel that is only 16 mm x 16 mm panel (with test points and controller mounted to the back). Each of these four-layer PCBs that makes up the completed cube contains an astonishing 950 mm of tracking, meaning the entire cube has nearly six meters of traces!
How do you power such a small device with no obvious places to locate a connector? By running magnet wire through a corner and down to a Qi coil of course. Not to let the cube itself outshine the power supply [Freddie] managed to deadbug a suitably impressive supply on the back of the coil itself. Notice the grain of rice in the photo to the left! The only downside here is that the processor – which hangs diagonally in the cube on a tiny motherboard – cannot be reprogrammed. Hopefully future versions will run programming lines out as well.
Check out the video of the cube in action after the break, and the linked photo album for much higher resolution macro photos of the build. While you’re there take a moment to admire the layout sample from one of the panels! If this sets the tone, we’re hoping to see more of [Freddie]’s going-away hacks in the future!
We see all kinds of projects come across the news desk at Hackaday. Sometimes it’s a bodge, neatly executed, that makes us laugh out loud at its simple ingenuity. Other times, it’s a case of great skill and attention to detail, brought to bear to craft something of great beauty. [Greg Davill]’s LED cube is firmly the latter.
The build starts with custom four layer PCBs, in matte black with gold-plated pads. It’s a classic color scheme, and sets the bar for the rest of the project. Rather than proceeding to hook up some commodity microcontrollers to off-the-shelf panels, [Greg] goes his own way. Each PCB gets a 24×24 raw LED matrix, directly soldered on the back side. By producing a “dumb” matrix, there are large savings in current draw to be had over the now-popular smart strings.
The panels are then loaded into a tidy 3D printed cube, with space inside for the FPGA running the show and a power supply. Five panels are held in with double sided-tape and screws, with the last being installed with magnets to allow access to the inside. Neatly folded flat-flex cables are pressed into service to connect everything up.
It’s a build that shows there is value in doing things your own way, and that the new methods don’t always beat out the old. With careful consideration of aesthetics from the start to the end of the project, [Greg] has built an LED cube both astounding in its simplicity, and beautiful in its execution. We’ve seen [Greg]’s work before, too – it’s not too often hand soldered BGAs cross these pages. Video after the break.
Like the tastes of the makers that build them, LED cubes come in all shapes and sizes. From the simplest 3x3x3 microcontroller test, to fancier bespoke installations, they’re a great way to learn a bunch of useful embedded techniques and show off at the same time. [kbob] has done exactly that in spades, with a glittering cube build of his own and published a repository with all the files.
Just like a horde of orcs from Mordor, [kbob]’s cube is all about strength in numbers. Measuring 136 mm on each side, it’s constructed out of 64 x 64 P2 panels, packing 4096 LEDs per side, or 24,576 total. A Raspberry Pi is used to run the show, allowing a variety of animations to be run. Unfortunately, it lacks the raw horsepower to run this many LEDs at a decent frame rate. Instead, it’s teamed up with an ICEBreaker FPGA, which can churn out the required HUB75 signals for the panels without breaking a sweat.
Thanks to the high density of tiny LEDs, and the smooth framerate of the animations, the final effect is rather gorgeous. [kbob] notes that there’s actually a lot of people working on similar projects with ICEBreaker muscle; a recent video from [Piotr] is particularly impressive.
There’s no doubting the allure of a nicely crafted LED cube; likewise, there’s no doubting that they can be a tremendous pain to build. After all, the amount of work scales as the cube of the number of LEDs you want each side to have, and let’s face it – with LED cubes, the bigger, the better. What to do about all that tedious lead forming?
[TylerTimoJ]’s solution is a custom-designed lead-forming tool, and we have to say we’re mighty impressed by it. His LED cubes use discrete RGB LEDs, the kind with four leads, each suspended in space by soldering them to wires. For the neat appearance needed to make such a circuit sculpture work, the leads must be trimmed and bent at just the right angles, a tedious job indeed when done by hand. His tool has servo-controlled jaws that grip the leads, with solenoid-actuated lead formers coming in from below to bend each lead just the right amount. The lead former, along with its companion trimmer, obviously went through a lot of iterations before [TylerTimoJ] got everything right, but we’d say being able to process thousands of LEDs without all the tedium is probably worth the effort.
There’s an easy way to signal to your friends and family that you’re a successful, urbane member of society – by decorating your home with tasteful references to popular culture. A classy oil painting of Yoda or a framed Tarantino movie poster is a great way to go. Alternatively, consider building yourself a swanky Rubik’s Cube lamp.
The build starts by disassembling the cube, as if you were going to cheat and reassemble it in the correct order. Instead, the cube is then gutted to make room for electronics. Inside, a ping pong ball covered in LEDs is installed, along with lithium batteries and a power board cribbed from a USB power bank. The whole assembly is laced back together with glue and frosted acrylic which acts as an retro-styled grid-like diffuser. The power button is even sneakily hidden in one of the squares!
It’s a sweet retro build that would make an excellent addition to any hip lounge room. We’re a big fan of self-contained glowing cubes here at Hackaday – we’ve covered nuclear powered and infinity designs before. Video after the break.
If there’s one thing that’s universally popular in these polarizing times, it’s colorful glowing objects. LEDs reign supreme in this area, and we’re accustomed to seeing all manner of fun flashy devices hit the tips line. Today is no different, and we’ve been looking at [Modustrial Maker]’s stylish epoxy LED cube.
The build starts with the casting of a black epoxy cube, with a cutout near the top in which the LEDs will be installed. A melamine form is used, with aluminium foil tape, caulk and paste wax to help seal it up. After releasing the cast from the form, there were some unsightly voids which were swiftly dispatched, by trimming the block down with a table saw. With the block cut to size, LED strips were installed, and the light cavity sealed with hot glue before white epoxy was poured in as a diffuser. All that’s left was a simple matter of polishing the cube and installing electronics.
The cube runs from a single-cell LiPo battery, and there’s a wireless power receiver and charging module to keep the power flowing. The cube can be used on most wireless phone chargers, as well as its own dedicated charging base. The LEDs are controlled by an off-the-shelf module, which offers a variety of flashing displays as well as a music-reactive mode.
While the electronics side is done with off-the-shelf parts, the real art in this piece is in the build of the cube. Its glossy, attractive form would look stunning on any coffee table or bedside shelf.