Adafruit has long been the undisputed ruler of the smart LED product, with their WS2812B (NeoPixel) and APA102C (DotStar) product lines dominating due to the robust assortment of sizes and form factors, as well as their ease of use. SparkFun Electronics recently announced Lumenati, their new line of APA102C breakouts that feature some intriguing features which do a good job of distinguishing the two lines.
First, the screen-printing on the boards include pixel numbers. We were working on NeoPixel assemblies the other day and keeping track of pixels was a nightmare. In addition, the Lumenati boards are meant to combine into larger creations, allowing you to make complicated shapes. SparkFun supports this by giving the boards castellated headers — far better than the solder pads! If you are running into logic conflicts with the boards you can solder in jumpers to bypass the data connections and control individual boards separately. On the down side, SparkFun’s intitial offerings — 6 products — still can’t compete with Adafruit’s, like their 255-LED disk, shields, strips, matrices, and flexible PCBs.
We’ve published a few DotStar builds over the years, like this violin bow lightsaber and the Magicshifter POV stick. Maybe we’ll start seeing some Lumenati builds? Continue reading “Look Out DotStar, Here Comes Lumenati”
We’re huge fans of [Neal Stephenson’s] work and are usually looking to assign some of his vision to the gear that pops up in the real world. But there’s no stretching or squinting necessary with this one. [Kerry Scharfglass] has built a functioning Drummer’s Badge from the foundational Sci-Fi novel The Diamond Age.
The badge is called Sympetrum, which is a genus of dragonfly. In explaining what the badge is and does, [Kerry] instructs you to go and read the book first and we couldn’t agree more. This isn’t recommended reading; if you’re a geek you need to read this book.
The dragonfly badges are from a portion of the book that gets pretty weird, but the gist is that rod-logic (machines build from microscopic carbon nanotubes) is so pervasive that at all times you’re covered in mites that are actually machines. At a party, one of the characters notices everyone is wearing dragonfly pins that begin to pulse with the music and synchronize with each other. They’re actually indicators of what the mites within the wearers’ bodies are doing — synchronizing people with other people.
This badge is a working recreation of that, presumably without the billions of mites controlling people (but who knows, it is DEF CON). At the center of the badge is an STM32 driving ten APA102 modules. Interactivity is based on IR signaling. The badge will cycle random color animations when alone. But each badge also projects clock sync and metadata over infrared, so put some of them in the same room and they’ll tend to synchronize.
Simple, beautiful, and a great geeky backstory. This example of Badgelife proves that hardware badges don’t need to be packed with features, or have a huge BOM cost. If done well, you can do an awful lot with just a little hardware and strong dose of inspiration. It also makes hand-assembly a lot more approachable, which is what you can see in the images above. Thanks [Kerry] for giving us an early look at this badge, can’t wait to see them at the CON.
We’ll be looking for this and all other #Badgelife offerings at DEF CON 25. Join us for a Hackaday meetup on Sunday morning as we once again do Breakfast at DEF CON
Commodity electronics manufacturing is a tough game. If you come out with a world-beating product, like WorldSemi did with the WS2812B addressable RGB LED “pixel”, you can be pretty sure that you’re going to be cloned in fairly short order. And we’re all used to horror stories of being sold clones instead of what was ordered. But what if the clones were actually an improvement?
[Gonazar] bought some strips of “WS2812” LEDs and prototyped a project. When stepping up to larger production, he thought he’d go directly to WorldSemi. Long story short, the cheaper LED modules that he’d previously bought weren’t from WorldSemi, but were actually SK6812 clones labelled as WS2812Bs. When he switched to the real thing, he discovered that they had some temperature and pressure sensitivities that the clones didn’t. The clones were better!
They weren’t even straight clones. It turns out that they have a much higher PWM frequency, resulting in less flicker at low brightnesses. The distributor came clean, saying that they swapped them out without note because they spoke the same protocol, but were a strict improvement.
Continue reading “WS2812B LED Clones: Work Better Than Originals!”
Hackaday was in Portland last weekend for the Open Hardware Summit. I did a brief recap earlier this week but this post has been on my mind the entire time. The night before the summit, OSH Park (the Purveyors of Perfect Purple PCBs which we all know and love) hosted a Bring-A-Hack at their headquarters. [Laen] knows how to throw a party — with a catered spread and open bar which all enjoyed. The place was packed with awesome hackers, and everyone had something amazing to show off.
In fact, there were far too many people showing off hardware for me to capture all in one evening. But join me after the jump for six or seven examples that really stuck out.
Continue reading “Look What Showed Up For Bring-A-Hack At OSH Park”
Persistence of vision projects were once all the rage, judging by a quick review of the literature here on Hackaday. They’ve tapered off a bit lately, but this impressive full-color globe display might just kick-start some new POV projects.
Built as a final project for an EE course, [Evan] and [Kyle]’s project is more about the control electronics and programming than the mechanical end of the build. Still, spinning a 12″ ring of 1/4″ thick acrylic with a strip of APA102 LEDs glued to the edge takes some thoughtful engineering. While the build appears sturdy, [Evan] does admit to a bit of wobble under full steam, which was addressed by adding some weight to the rig. We wonder if mounting half the LEDs on each side of the ring to balance the forces wouldn’t have worked better. True, it would have complicated the coding for the display, but maybe that would have been good for extra points. In any case, the display turned out well and the quality of the images is great. And as an aside: how awesome is it that we live at a time when you can order a six-circuit slip-ring for a project like this for less than $20?
It’s the end of the semester and we love seeing the final projects that have just made it across the finish line. This globe is one, yesterday we saw a voice-controlled digital eye exam, and if you have or know of a final project, don’t forget send us the link!
If POV globes are your thing, be sure to set the Hackaday WABAC machine a few years and check out this Death Star design from 2012 or this globe from 2010.
Some people would look at a massive 6’x4′ LED matrix hanging on the wall playing animations and be happy with the outcome. But [Ben] just isn’t one of those people. The original FLED (Fantastic LED thingy) was eight rows of twelve addressable LEDs for a total of 96 pixels. This spring he upped his game and retrofitted the display with 1768 LEDs.
It wasn’t simply an issue of restlessness, the original build suffered from LEDs dying. We actually featured it for that reason as a Fail of the Week. This is not strictly a hobby project, it’s hanging on the wall in the Supplyframe offices, so pulling it down frequently to fix broken parts is not ideal.
To make FLED more reliable [Ben] sourced strips of the new APA102 LEDs which we looked at back in December. They use an SPI bus instead of the bizarre timing scheme of the WS2812. At first glance you’d think this would mean easier assembly compared to soldering both sides of each of the original 96-pixels. These do come in strips, but laying out 52×34 still means soldering to the ends of each row.
A lot of love went into making sure those rows were laid out perfectly. A sheet of white foamed PVC serves as the substrate. There is grounding braid on either end of the rows, one is the voltage bus, the other is ground. It fits the original enclosure which is acrylic and does a great job of diffusing the light. I’ve seen it in person and it looks pretty much perfect!
It’s not just the physical layout of this many pixels that is a challenge. Pushing the data to all of them is much harder than it was with 96. [Ben] transitioned away from RaspberryPi. He considered using a Teensy 3.1 and ESP8266 but the WiFi of these cheap modules is far too slow to push frame information from a remote box. In the end it’s a BeagleBone Black that drives the reborn display. This is a great choice since there’s plenty of power under the hood and a traditional (and much faster) WiFi dongle can be used.
Don’t miss the animation demos found after the break.
Continue reading “1768 LEDs, Because 96 Just Wasn’t Enough”
[Tim] got his hands on some APA102 RGB LEDs, which are similar in function to the common WS2812 addressable LEDs seen in many projects we’ve featured. The advantage of APA102 LEDs is that they don’t have the strict timing requirements of the WS2812. These LEDs are controlled with a SPI bus that can be clocked at any arbitrary rate, making them easy to use with pretty much any microcontroller or embedded system.
After working with the LEDs, [Tim] discovered that the LEDs function a bit differently than the datasheet led him to believe. [Tim] controlled a strand of APA102 LEDs with an ATtiny85 and connected a logic analyzer between some of the LEDs. He discovered that the clock signal of the SPI interface isn’t just passed through each LED, it actually looks like it’s inverted on the output. After some investigation, [Tim] found that the clock signal is delayed by a half period (which looks like an inversion) before it’s passed to the next LED. This gives the next LED in the strand enough time for data on the data line to become valid before latching it in.
Since the clock is delayed, [Tim] discovered that additional bits must be clocked as an “end frame” to generate clock signals which propagate the remaining data to the end of the strand. Although the datasheet specifies a 32-bit end frame, this only works for strings of up to 64 LEDs. More bits must be added to the end frame for longer strands, which the datasheet doesn’t even mention. Check out [Tim]’s post for more information, where he walks you through his logic analysis of the APA102 LEDs.