Hackaday.io contributor extraordinaire [al1] has been playing around with small LEDs a lot lately, which inevitably leads to playing around with large groups of small LEDs. Matrixes of tiny RGB LEDs, to be precise.
First, he took 128 0404 SMD RGB LEDs (yes, 40 thousandths of an inch on each side) and crammed them onto a board that’s just under 37 mm x 24 mm. He calls the project 384:LED (after all, each of those 128 packages has three diodes inside). A microcontroller and the driver chips are located on a separate driver board, which piggy-backs via pin headers to the LED board. Of course, he had to use 0.05 inch headers, because this thing is really small.
Of course, no project is without its hitches. [al1] bought LEDs with the wrong footprint by mistake, so he had a bunch of (subtly different) 0404 LEDs left over. Time for an 8×8 matrix! 192:LED isn’t just the first project cut in half, though. It’s a complete re-design with a four-layer board and the microcontroller on the back-side. And as befits a scrounge project with lots of extreme soldering, he even pulled the microcontroller off of a cheap digital FM radio. Kudos!
We’re in awe of [al1]’s tiny, tiny hacking skills. Now it’s time to get some equally cool graphics up on those little displays.
RGB LED cubes are great, but building the cube is only half the battle – they also need to be driven. The larger the cube, the bigger the canvas you have to exercise your performance art, and the more intense the data visualization headache. This project solves the problem by using Unity to drive an RGB LED cube in real-time.
We’re not just talking about driving the LEDs themselves at a low level, but how youwhat you want to display in each of those 512 pixels.
In the video, you can see [TylerTimoJ]’s demo of an 8x8x8 cube being driven in real-time using the Unity engine. A variety of methods are demonstrated from turning individual LEDs on and off, coloring swaths of the cube as though with a paintbrush, and even having the cube display source image data in real-time (as shown on the left.)
Quick–in a pinch, let’s have ourselves a giant RGB LED Matrix! As marvelous as it sounds, it’s pretty easy to forget that there’s a battle to be won against picking the right parts, debugging drivers, and sorting out our spaghetti wiring. Rest assured, [Hzeller] has done all of the heavy-lifting for us with a Raspberry Pi RGB LED Matrix Implementation that scales to multiple panels and runs on any Pi model to date!
Offering 24-bit color at about 100 Hz for up to a grand total of 36 panels, [Hzeller’s] library is no slouch. The library enables customization of your panel arrangements, and a separate project (also [Hzeller’s] handiwork) makes this setup compatible with the pixel-pusher protocol as a network device.
It’s certainly true that many of ushaveathing for these displays, so you might ask: “have we seen this before? What’s all the fuss?” Like the others, the final product is a sight to behold, but [hzeller] and his implementation stands strong because of his phenomenal response to answering the question: how? In fact, almost more impressive is his comprehensive online documentation. Inside, [hzeller] details various hardware configurations for a custom number of panels or a particular flavor of Pi that drives them. He also provides references for pinout quirks and provides out-of-the-box software demos to ensure that anyone can bring this project to life. If a poorly-written or non-existent READMEs have made you shy away from building on an open-source project, fear not. From pinout quirks and out-of-the-box software demos, [hzeller] has covered all the bases and given us a project that folks of all levels of hacking.
Perhaps the best part of this project is the span of the audience that can take something away from it. If you’re a seasoned Linux junkie, dive into the source code to get a good feel of mechanics of how [hzeller] pushes this project onto a single core in a Raspi-2 configuration. If you’re new to digital electronics, let this project be your moment to pick up a Pi, a panel (or four), and run, knowing that [hzeller’s] README is the only tome you’ll need to light up the night.
One of our chief complaints about the Raspberry Pi is it doesn’t have a lot of I/O. There are plenty of add ons, of course to expand the I/O capabilities. The actual Raspberry Pi foundation recently created the Sense Hat which adds a lot of features to a Pi, although they might not be the ones we would have picked. The boards were made for the AstroPi project (the project that allowed UK schools to run experiments in space). They don’t appear to be officially for sale to the public yet, but according to their site, they will be selling them soon. Update: Despite some pages on the Raspberry Pi site saying they aren’t out yet, they apparently are.
What happens when you take over 800 individually addressable super bright RGB LEDs and house them in a giant diffused panel? You get awesome. That’s what you get.
[Epoch Rises] is a small electronic music and interactive technology duo who create cool interactive projects (like this wall) for their live shows and performances. They love their WS2812B LEDs.
The cool thing about this wall is that it can take any video input, it can be controlled by sound or music, an iPad, or even generate random imagery by itself. The 800 LEDs are controlled by a Teensy 3.0 using the OctoWS2811 library from Paul Stoffregen which is capable of driving over 1000 LEDs at a whopping 30FPS using just one Teensy microcontroller. It works by using Direct Memory Access to send data over serial into the Teensy’s memory and directly out to the LEDs with very little overhead — it is a Teensy after all!
The folks at NYC Resistor have a thing for circular displays, it seems. Their earlier Hexascroller was a ceiling mounted display with six 30×7 displays – good enough to display the time and a few textual message in six directions. The Octoscroller bumped up the display capability with eight 16×32 RGB LED panels. Now the Megascroller, a 32-sided 512×64 display is hanging in the hackerspace, complete with 360° Mario and Pong.
The Megascroller is one of [Trammell Hudson]’s projects, constructed out of sixty-four 32×16 RGB LED matrices. That’s an impressive amount of controllable LEDs, that required a lot of processing power: namely, the BeagleBone-powered LEDscape board used in their earlier Octoscroller
As far as applications go, they naturally have Pong, but a more interesting application is the side-scrolling Mario that requires you to move around the display as you play. You can check out a video of that below.