A Levitating Lamp Without Magnets

June 10, 2020 by Moritz v. Sivers 9 Comments

If you think of levitating objects you probably think about magnets but this is not what [Aaron Hung] used to build his levitating LED lamp. To be fair, his lamp is not really levitating but merely generates the illusion through the principles of tensegrity. We have featured a number of tensegrity structures over the last months but this is maybe the first time somebody has used it to build a daily-use item.

In his instructable [Aaron Hung] points out that according to Earnshaw’s theorem magnetic levitation using static magnetic fields like those of permanent magnets is actually impossible. If you are interested, the Wikipedia article also explains why floating superconductors and the Levitron toy do not contradict this theorem. (TL;DR: they’re dynamic.)

Coming back to [Aaron Hung]’s tensegrity lamp, the construction is rather simple and only requires an Arduino Nano, a Neopixel ring, a 9 V battery some wood or cardboard, and fishing line. The tensegrity part of the lamp consists of two similar pieces of laser-cut wood which are held together by fishing line so that the top part seems to float in mid-air. Normally, tensegrity structures are very fragile so [Aaron Hung] added some extra lines for stability which allowed him to hang the lamp from the top section without collapsing the whole structure. After coding some animations for the Neopixel ring and adding a paper lampshade the project was finished.

We would like to see more tensegrity versions of classic DIY projects and it was fun to see that similar objects were already built from Lego.

[Video after the break].

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UV Phone Sanitizer Shows The Power Of Modern DIY

June 8, 2020 by Tom Nardi 94 Comments

Editor’s Update: According to the schematic for this project, SST-10-UV-A130-F405-00 (PDF) LEDs are used which produce 405nm UV-A light. The manufacturer, Luminus, does not recommend that part for disinfection or sterilization. Luminus sells UV-C LEDs for that purpose, generating 275-285nm. After publication the part number used was changed to and American Opto L933-UV265-2-20 which is a UV-C LED producing 265-278nm.

The global COVID-19 pandemic has had a serious impact on the hacking and making scene, though it hasn’t been all bad. Sure, shipping on average is taking a lot longer than we’d like when ordering parts, but otherwise being stuck at home has given many people far more time to work on their projects than they would have had otherwise. In some cases, it’s also been a reminder of just how far we’ve come in terms of what the dedicated individual is capable of producing within the confines of their own home.

As a perfect example, take a look at this UV sanitizer box built by [Md Raz]. Looking for a way to quickly and easily kill germs on smartphones and other small devices, he used the considerable capabilities afforded to the modern hacker to produce a professional-looking device in far less time than it would have if he had to outsource things like PCB manufacturing or injection molding.

Inside the 3D printed enclosure is an array of SMD UV-C LEDs that, according to the manufacturer’s specs, will destroy viruses and bacteria in 5 minutes. To make sure the LEDs are given enough time to do their job, [Md] is using an ATtiny85 to control the countdown and a seven segment display to let the user know how much longer they have to wait. All the electronics are held on PCBs produced with a BotFactory SV2 desktop PCB printer, but for those of us with somewhat more limited budgets, a mill or even a modified laser engraver could be used to produce similar boards.

With everything going on, there’s understandably been increased demand for germicidal lights. But unfortunately, some unscrupulous manufacturers are trying to take advantage of the situation. Being able to select the LEDs for this device based on their specifications is arguably just as important as how quickly it was produced. Though we’d still advise a position of “trust, but verify” when it comes to UV-C.

A Look Behind The Canvas Of The “60 Billion Lights” Project

June 8, 2020 by Maya Posch 17 Comments

In May of this year, [Erich Styger] shows his project called “60 Billion Lights” off to the world. Now he has published an update on the making of this impressive work of art. As a quick recap, “60 Billion Lights” is a canvas art piece, which has 60 dual shaft stepper motors integrated into it. Each stepper motor has forty 24-bit RGB LEDs, making for a total of 60 billion position and light combinations on the entire canvas.

With the dual shaft stepper motors, one can control the position of laser-cut acrylic rods inside each of the forty depressions that make up a unit. Each unit has its WS2812B LEDs positioned around the inside edge.

As the embedded video (after the break) shows, it can be used to create a wide variety of effects. The whole of it is driven by 15 controller boards that run FreeRTOS on an NXP LPC845 (Cortex-M0+), connected via RS-485.

In the ‘Making Of’ video (embedded after the break) and article, more details are shown of the individual components, including the dual shaft stepper motors, stepper motor PCBs, the LED ring PCBs, and countless images of the construction, painting and assembly.

If the original article gave one the impression that this was an easy project, it is this behind the scenes look that gives one a good impression of the full scale. From the countless PCBs, controller boards, wiring, programming to the assembly and testing. Not to mention the painting of the canvas itself, which is an original work.
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Cheap Party Light Gets Arduino Upgrade

June 6, 2020 by Tom Nardi 22 Comments

If you’ve got a party coming up and are looking to add a little bit of excitement, you might be interested in this recent project from [Gav Lewis]. The build is based on a commercially available party light, but with some upgraded components the final product is brighter and more dynamic than it was stock.

Realistically, [Gav] has changed out almost every component of this light except for the enclosure and the front lens. The original 5 mm LED array was replaced with a new 8×8 WS2812B panel, and the electronics completely replaced with an Arduino Nano. He’s still using the light’s original power supply, but as it only puts out around 4.2 V, he’s added a boost converter to provide a stable 5 V for the new hardware. He also added a small 12 V cooling fan, which he says is basically silent since it’s only getting half its rated voltage.

[Gav] has developed a number of lighting patterns with FastLED that do a good job of emulating what you might see from a much more expensive laser scanner. In the video after the break, you can see how multiple colored beams of light exit the housing at once, projecting patterns on the opposite wall. He says he’s like to restore the device’s original sound activation mode, but as of yet hasn’t gotten the code sorted out.

This project uses a off-the-shelf 8×8 matrix of WS2812B LEDs, but if you ever find yourself needing to piece together your own array from individual LEDs, we recently covered a great tip for making it a bit easier.

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Rolling Your Own LED Matrix Driver, With Copper Foil Tape To The Rescue

May 30, 2020 by Donald Papp 1 Comment

It all started when [Damien Walsh] got his hands on some surplus LED boards. Each panel contained 100 mini-PCBs hosting a single bright LED that were meant to be to be snapped apart as needed. [Damien] had a much better idea: leave them in their 20×5 array and design a driver allowing each LED to be controlled over WiFi. He was successful (a brief demo video is embedded down below after the break) and had a few interesting tips to share about the process of making it from scratch.

The first hurdle he ran into was something most of us can relate to; it’s difficult to research something when one doesn’t know the correct terms. In [Damien]’s case, his searches led him to a cornucopia of LED drivers intended to be used for room lighting or backlights. These devices make a large array of smaller LEDs act like a single larger light source, but he wanted to be able to individually address each LED.

Eventually he came across the IS32FL3738 6×8 Dot Matrix LED Driver IC from ISSI which hit all the right bases. Three of these would be enough to control the 100-LED panel; it offered I2C control and even had the ability to synchronize the PWM of the LEDs across multiple chips, so there would be no mismatched flicker between LEDs on different drivers. As for micontroller and WiFi connectivity, we all have our favorites and [Damien] is a big fan of Espressif’s ESP32 series, and used the ESP32-WROOM to head it all up.

LED pads bridged to copper tape, with Kapton (polyimide) tape insulating any crossovers.

The other issue that needed attention was wiring. Each of the LEDs is on its own little PCB with handy exposed soldering pads, but soldering up 100 LEDs is the kind of job where a little planning goes a long way. [Damien] settled on a clever system of using strips of copper tape, insulated by Kapton (a super handy material with a sadly tragic history.) One tip [Damien] has for soldering to copper tape: make sure to have a fume extractor fan running because it’s a much smokier process than soldering to wires.

A 3D-printed baffle using tracing paper to diffuse the light rounds out the device, yielding a 20 x 5 matrix of individually-controlled rectangles that light up smoothly and evenly. The end result looks fantastic, and you can see it in action in the short video embedded below.

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Dim Hallway Gets Lighting Upgrade

May 27, 2020 by Lewin Day 13 Comments

There’s nothing worse than a lightswitch that’s nowhere near where it should be, leaving you fumbling around in the dark. [supersquirrel72] had just this problem, and decided to put an Arduino to work instead.

Rather than using the original mains lighting that was poorly positioned and not enough to light the hall, instead 2 meters of white LED strip was chosen. The form factor is perfect for lighting a long, thin space – far better than running a series of seperate bulbs. The strip was rigged up to an Arduino Uno, that triggers the lights when movement is detected with a simple PIR motion sensor. After some feedback from the other occupants of the house, it was decided to tweak things further. An RTC was implemented to allow the Arduino to keep things dimmer after 9PM, so as to not wake others when making a trip to the kitchen for a midnight snack.

It’s a simple solution which brightens up the hallway nicely. We imagine this could just be the first step to a yet-more-integrated lighting solution in [supersquirrel72]’s house. Whether it’s IOT lights or something more festive, we can’t wait to see what’s next.

From Zero To LED Cube In Less Than Seven Months

May 22, 2020 by Dan Maloney 17 Comments

We know that LED video cubes are so last year, but that doesn’t mean we don’t still love to see them. Any project that incorporates over 24,000 LEDs is bound to be impressive, after all. But the more interesting bit about [Mike Cann]’s self-contained LED cube has more to do with the process he chose to get to the finished product.

There are two ways to approach a new project, especially when you’re new to hardware hacking like [Mike] is. One is to jump in with both feet and just see what happens, for good or for ill. The other is is to ease into it with a starter project, to find out where your limitations lay and work around them gradually. [Mike Cann] wisely chose the latter approach with his LED cube project, starting with an LED sand toy. The single 64 x 64 LED panel was a bit easier to work with, and got him up to speed on the care and feeding of such hardware, as well as the code needed to drive it. The video below tells the tale of scaling that project up by a factor of six to make the cube, a process that had its share of speedbumps. Everything ended up fitting together great, though, letting [Mike] get on to the software side. That’s where this project really shines — the smartphone app running the cube is really slick, and the animations are great.

There’s clearly room for new features on [Mike]’s cube, so here’s hoping he can carve out some time to make a great build even better. For inspiration he might want to check out this side-scrolling Castlevania cube, or perhaps read up on the finer points of OpenGL for LED cubes.

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