Breadboardable WS2812 LEDs

February 22, 2014 by Brian Benchoff 21 Comments

LED

Hackaday sees a ton of projects featuring the WS2812 series of digitally controllable RGB LEDs, in the form of bare chips, RGB LED strips, or some form of Adafruit’s NeoPixels. All these WS2812 LED products have one thing in common – they’re chip LEDs, making some projects difficult to realize. Now there’s a new member of the WS2812 family – a through-hole LED version – that should be available through the usual sources sometime later this year.

The key difference between these and the usual WS2812 LEDs is the packaging; these are 8mm LEDs with pins for power, ground, data in, and data out. With the preexisting libraries, this 8mm LED should work just the same as any other WS2812 LED.

Aside from a through-hole package, these new LEDs are very diffuse and aren’t as blinding as the normal chip LEDs. If you want to pick up a few of these LEDs, they’re available here, 13 LEDs for $15. There’s a lot of potential here for RGB LED cubes, something we hope to see sooner rather than later.

Companion Cube Christmas Lights Improved With Neopixels

February 20, 2014 by Brian Benchoff 3 Comments

cubes

[Crenn] obtained a string of official companion cube lights from Valve, but being in Australia couldn’t put them to their non-judgemental glory without the use of a step down transformer. They sat on the workbench for a few months until an idea was hatched: replace the bulbs with an Adafruit Neopixel strip, making these wonderful inanimate friends a string of individually addressable RGB LEDs.

The process of converting these cubes required stuffing a very small 9.4mm PCB inside. This PCB was designed in KiCAD thanks to a few classes at the Melbourne hackerspace. The board files were sent off, PCBs received, soldered up, and stuffed into the cubes.

Control is via a Duemilanove with a single IO pin using the Neopixel library. All the code, board files, and schematics are available on the gits. Future improvements might include a 3D printed cable relief and a way to securely mount the PCBs to the inside of the cubes.

Video available below.

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Controlling Ten Thousand RGB LEDs

January 2, 2014 by Brian Benchoff 51 Comments

RGB LEDs are awesome – especially the new, fancy ones with the WS2812 RGB LED driver. These LEDs can be individually controlled to display red, green, and blue, but interfacing them with a microcontroller or computer presents a problem: microcontrollers generally don’t have a whole lot of RAM to store an image, and devices with enough memory to do something really cool with these LEDs don’t have a real-time operating system or the ability to do the very precise timing these LEDs require. [Sprite_tm] thought about this problem and came up with a great solution for controlling a whole lot of these WS2812 LEDs.

[Sprite] figured there was one device on the current lot of ARM/Linux boards that provides the extremely precise timing required to drive a large array of WS2812 LEDs: the video interface. Even though the video interface on these boards is digital, it’s possible to turn the 16-bit LCD interface on an oLinuXino Nano into something that simply spits out digital values very fast with a consistent timing. Just what a huge array of RGB pixels needs.

Using a Linux board to drive RGB pixels using the video output meant [Sprite_tm] needed video output. He’s running the latest Linux kernel, so he didn’t have the drivers to enable the video hardware. Not a problem for [Sprite], as he can just add a few files to define the 16-bit LCD interface and add the proper display mode.

[Sprite_tm] already taken an oscilloscope to his board while simulating 16 strips of 600 LEDs, and was able to get a frame rate of 30 fps. That’s nearly 10,000 LEDs controlled by a single €22/$30USD board.

Now the only obstacle for building a huge LED display is actually buying the RGB LED strips. A little back-of-the-envelope math tells us a 640×480 display would be about $50,000 in LEDs alone. Anyone know where we can get these LED strips cheap?

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Finally, An Animated GIF Light Painter

December 12, 2013 by Brian Benchoff 6 Comments

led_strips_dragon-flap

Light painting, or taking a picture of a moving RGB LED strip with a very long exposure, is the application du jour of Arduinos, photography, and bright, glowey, colorful things. Hackaday alumnus [Phil Burgess] has come up with the best tutorial for light painting we’ve seen. It’s such a good setup, it can be used to create animated .gifs using multiple camera exposures.

The build uses an Arduino Uno, SD card shield, and Adafruit’s new NeoPixel strip with 144 RGB LEDs per meter. Despite a potentially huge mess of wires for this project, [Phil] kept everything very, very neat. He’s using an Altoids case for the ‘duino, an 8 AA-cell battery holder and 3A UBEC for the power, and a wooden frame made out of pine trim.

Part of the art of light painting involves a lot of luck, exponentially so if you’re trying to make a light painted animated .gif. To solve this problem, [Phil] came up with a very clever solution: using a rotary encoder attached to a bicycle. With the rotary encoder pressed up against the wheel of a bike, [Phil] can get a very precise measurement of where the light strip is along one dimension, to ensure the right pixels are lit up at the right time and in the right place.

It’s a wonderful build, and if Santa brings you some gift certificates to your favorite electronics retailer, we couldn’t think of a better way to bring animated .gifs into the real world.

Turning A Storefront Into A Video Game

November 27, 2013 by Brian Benchoff 17 Comments

invasion

[Kris]’ house/office has a huge store window, and instead of covering it up with newspapers, decided to do something cool. He’s had projections and other art pieces on display for his neighbors, but his new storefront arcade game very likely beats all of those.

Every video game needs a display, and this one is no slouch. The display is a 16*90 matrix of WS2812 LEDs with inset into a laser cut grid and put behind a layer of plexiglass. With this grid, the display has a great raster effect that’s great for the pixeley aesthetic [Kris] was going for. In front of the window is an MDF and steel arcade box powered by an Arduino Due.

The game is driven by the Adafruit neopixel library, with a few modifications to support alpha blending. There’s no external memory for this game – everything is running on a second Arduino Due inside the window.

It’s a great looking game, and if you’re ever in [Kris]’ area – behind the zoo in Antwerp – you’re free to walk up and give this game a spin.

Video demo below.

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Monitor GitHub Activity With An RGB LED Matrix

October 16, 2013 by Adam Fabio 2 Comments

tim-display

Ever wonder who is forking your code? [Jack] did, so he built a real time GitHub activity display for his company’s repositories. The display is based a Wyolum The Intelligent Matrix (TiM) board. The TiM is an 8 x 16 matrix of the ubiquitous WS2811/Smart Pixel/NeoPixel RGB LEDs with built-in controller. We’re seeing more and more of these serial LEDs as they drop in price. Solder jumpers allow the TiM to be used as 8 parallel rows of LEDs (for higher refresh rates), or connected into one long serial chain.

[Jack] wasn’t worried about speed, so he configured his board into a single serial string of LEDs. An Arduino drives the entire matrix with a single pin. Rather than reinvent the wheel, [Jack] used Adafruit’s NeoMatrix library to drive his display. Since the TiM uses the same LEDs as the Adafruit NeoPixel Matrix, the library will work. Chalk up another victory for open source hardware and software!

An Electric Imp retrieves Github data via WiFi and passes it on to the Arduino. This is a good use of a microcontroller such as the AVR on the Arduino. [Jack’s] display has a scrolling username. Every step in the scroll animation requires all the pixel data be clocked out to the TiM board. The Arduino can handle this while the IMP takes care of higher level duties.

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The Greenest Wall-Powered Clock

October 13, 2013 by Brian Benchoff 51 Comments

Some of the most inefficient appliances in the home are AC mains-powered clocks. You can’t exactly turn them off and they use a whole lot of energy considering how often they’re looked at. [t3andy] came up with a great low power AC Mains clock that is only on 3% of the time. As a neat bonus, it also looks really, really cool.

[t3andy] is using a Teensy 3 as the brains of this clock, and the serial interface on the board provides a relatively easy means of setting the time without having to use buttons or tact switches. The clock face consists of 13 neopixels, with two red pixels showing the hour and a single green pixel showing the minutes. The time is measured with a DS3232 I2C real time clock with a battery backup.

The design is remarkably efficient since the LEDs are off 97% of the time, only being lit at the top of the minute. There are provisions for IR control and a PIR sensor to display the time whenever it’s needed, but that would obviously mean a hit to the energy efficiency.