LED Hacks

1843 Articles

Paint Your Pictures, No PC Needed

January 30, 2012 by 14 Comments

LEDs and and cameras always make a fun mixture, and its not all that hard to have quite a bit of fun as well. The Light Painting Stick is similar to other long exposure camera tricks like LightScythe and gets about the same reults. The difference is the Light Painting Stick is self contained meaning you don’t have to drag nearly as much stuff along with you to have fun.

Hardware used is HL1606 controlled RGB led strip commonly found at Adafruit, the brains are a Leaf Labs Maple micro controller board with an SD card and some human interfaces attached, and is powered by a 6 volt lantern battery.

Images are 64*infinity 24 bit BMP files which means there is not much fuss preparing your graphics other than doing a simple rotate. You can select which image is displayed by using a 2 way switch and the LEDs on the stick. Select your images, dial in your speed with the potentiometer, and you’re  ready to hit the fire button for some photo fun.

Followup: Troll Physics Solved

January 27, 2012 by 48 Comments

A month ago, we saw a marvelous demonstration of troll physics from YouTube user [Fredzislaw100]. In his video, we saw a circuit of three switches and three LEDs wired in series and but not acting like the should. A lot of the comments for this post elicited reasonable explanations like modifying the battery or pure camera wizardry via After Effects. Thankfully, [Alan] stepped in and showed us how it was done. The solution uses two AC power sources with diodes in two of the switches and LEDs and inductors in the third pair. [Alan]’s build was rather large compared to the original video, so we were wondering how this circuit could be made invisible.

[Fredzislaw100] just posted a video on how he did it. Like [Alan]’s build, it uses two AC power sources, diodes, and inductors. In contrast to every single guess about where the circuit is hidden, the majority of the build is inside the battery connector. [Fredzislaw] did some amazing work hiding a 74LV132 quad NAND Schmitt trigger inside the battery connector. The diodes were easily hidden on LEDs 1 and 3 with some red nail polish, but we’re amazed by the inductor built into the LED seen in the title pic.

So there you go. With a ton of electronics know-how and an extremely steady hand (and a microscope), you too can build your own troll circuit. Check out the video after the break.

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Sixty4Racer An 8×8 Game

January 27, 2012 by 2 Comments

[Pete] has a cool new tutorial creating a re-imagining of the Atari classic “River Raid” for the PIX-6T4 micro controller based game system. The PIX is a netduino on a larger board featuring 2 analog controllers, a speaker, an sd card and an 8×8 monochrome LED display. With a resolution that low, it may make the good ole VCS look like a 360, but there is still a lot to learn about making a game at this low of a level.

The tutorial [Pete] has put together covers concept, gameplay, progression goals, screen handling and a boat load of code to show how it all goes together. Though this is for a C# based system many of the basics apply to just about any system you can imagine. So if you’re looking to learn how to handle graphics in C, sprite animation, collision, or randomly putting levels together out of tile blocks then you should take a look.

Join us after the break for a quick video.

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Rotary Phone-light-amp Could Be Filed Under Bizarre

January 25, 2012 by 18 Comments

[Samimy’s] latest project is a little strange, but one man’s weird is another man’s wonderful so we’re not about to start criticizing his work. Nope, we’re here to praise the fact that his rotary phone turned reading light and audio amp is very well constructed.

He started by removing the phone housing. Those old enough to have used one of these devices will remember their bulk, and there’s a lot of unused space in both the handset and body housing. [Samimy] started by removing the speaker and microphone from the handset, and drilling a ring of holes to receive white LEDs. The circuit was wired so that lifting the handset turns on the lights.

But he didn’t stop there. A set of speakers and the audio amplifier circuitry from an old tape deck are also hiding inside the base of the phone. If you look closely in the image above you can see that he’s connected his cellphone and is listening to some tunes through the antique hardware. Take a gander at the video after the break to see construction and use of the project.

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Matrix Backpack Was A Fun Design Project

January 23, 2012 by 7 Comments

[Greg] is really working on a small scale with his LED Matrix backpack PCB. It’s a toy that he designed as an activity. He constrained himself to a board which would exactly match the outline of an 8×8 bicolor LED matrix package.

What you see here is the side of the PCB which will be facing the underside of the LED dot matrix module. Let’s call this the top of the board. The underside has a CR2032 battery holder which provides enough juice to run the display. Since the matrix is bi-color there’s a slew of pins to drive. [Greg] uses three shift registers for the high side, and sixteen N-channel MOSFETS for the low side. He’s chosen an MSP430G2201 microcontroller which has a nice sleep mode for power conservation. It has no problem driving tri-color animations as seen the clip after the break, but also has an unpopulated clock crystal footprint if you wanted to use it as a timepiece.

Despite the small footprints and cramped board [Greg] still hand soldered all of the components. He even posted a time-lapse of the process in the page linked at the top.

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Tubular POV Display

January 20, 2012 by 19 Comments

[Ryan]’s cylinder POV display is an amazing piece of work. Right now it’s impressive sitting on his workbench, but we’re sure it would be astonishing hanging above the middle of a dance floor. There are 64 RGB LEDs on this display and they’re certainly bright enough to liven up any space.

Power is provided through a slip ring. The ground is connected to the shaft of the motor [Ryan] picked up at an auto parts store. It’s an efficient way to do things, but the display can only be controlled by whatever image is stored in the ATMega1284’s flash memory. [Ryan] admits this isn’t an ideal setup so he’s working on a ZigBee or Bluetooth connection.

We’ve seen some amazing spinny POV cylinders, but [Ryan]’s build looks amazingly professional. All the board files, schematics and code are uploaded, as well as an image converter for BMPs and PNGs. Check out the demo after the break.
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Controlling A Cute Ikea Night Light With Android On The Cheap

January 19, 2012 by 12 Comments

When [trandi]’s wife saw a cute night light at Ikea, she had to have it. She actually bought several of these for when her husband would inevitably crack one open and start tinkering with the microcontroller inside. The inevitable hack is pretty cool, and also gives us some ideas for interfacing with Android on the cheap.

The build started as an Ikea Spoka night light, an adorable anthropomorphized night light with a squishy silicone skin. Inside the Spoka are a dozen tri-color LEDs that [trandi] can cycle through with the push of a button. After deciding to control the lights inside the Spoka with an Android phone he reached for an IOIO Android breakout board. Fate intervened and [trandi] ended up with a ridiculously cheap Bluetooth modules that provides a simple serial connection to other Bluetooth devices.

The build reuses the blue, red, orange LEDs in the night light but replaces the no-name 8-pin micro with an ATtiny2313. [Trandi] wrote a small Android app to control the color over a Bluetooth serial connection. Check out his demo after the break.

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