LED Hacks

1830 Articles

This LED Table Really Ties The Room Together

April 13, 2012 by 6 Comments

led-matrix-table

Along with quadrotors, and portable game consoles, one of the hacks we never get tired of seeing is an LED matrix table. [Christian Enchelmaier] wrote in to share his take on the ever popular pixelated furniture, which we think came out pretty well (Translation).

Instead of going for a full-sized coffee table, [Christian] decided to keep things on the smaller scale his first time out, opting for an ottoman/end table nstead. He constructed a 16×16 matrix using RGB LEDs, encapsulating each one in its own “pixel”, as is common with these builds. [Christian] uses an Atmega 128 to run the show, displaying the current time and date, temperature, music visualizations, games, images, along with short videos. He also outfitted the table with an IR receiver so that he can control the table’s display from afar.

As of right now, [Christian] doesn’t have any video of the table in action, but there’s plenty in the way of pictures scattered throughout his build log to keep you busy in the meantime.

Infrared Hides Code Combination On Geocache Puzzle

April 12, 2012 by 11 Comments

[AJ] and [Brian] are making sure the geocache challenges they set up take some ingenuity to solve. They’ve just rolled out a two-part cache which uses a code hidden in infrared light.  (Editor’s note from the far future: link wend dead.  Have a look in the Wayback Machine.)

The first part of the cache is a box (the black one on the left) which contains a mysterious hand crank and a smaller box that has a combination lock on it. The second stage is the wooden box on the right. It’s got a hole in the side to receive the hand crank. This connects to the dynamo inside, letting you build up some electricity as it spins. Inside the case you’ll see two red lights blink as the crank is turned, but when you push the button on the outside of the box nothing will happen. That is, unless you’re looking through a camera which can pick up infrared light. The code (710 in this case) is displayed in an array of IR LEDs, and is used to open that combination lock. We wonder if there’s any clues about using a camera or if you have to figure this out on your own.

Don’t miss the video after the break for a full demo of the system.

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The Best LED Cube Build We’ve Seen

April 6, 2012 by 28 Comments

[Nick] wrote in telling us about the LED cube he built over the course of six months. He calls LED cubes ‘done to death,’ but [Nick] might be too humble. His 8x8x8 RGB LED cube is the best we’ve ever seen.

To start his build, [Nick] built a simple 4x4x4 cube as a proof of concept. The baby cube worked but the fabrication process got him thinking. Instead of building his monster LED cube in layers from the bottom up, he would need to build columns from left to right. After the construction of a jig, soldering eight panels of 64 LEDs, and buying a new soldering iron tip, [Nick] had a beautiful assembled LED cube. The only thing missing was the electronics.

Most of the LED cubes we’ve seen use the TLC5940 LED driver for hardware PWM, [Nick] decided to go with the simpler but more familiar STP16 chip. After hooking up his huge LED driver board up to a chipKIT Uno, the 80 hours of programming began.

In the end, [Nick] built the best LED cube we’ve seen (even though it isn’t the largest) and put together one of the best build logs in recent memory. Because no LED cube build is complete with out a video there’s an awesome demo after the break.

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Display Made Out Of Hundreds Of Seven Segment LEDs

March 30, 2012 by 23 Comments

While huge LED panels are a relatively common project du jour for people wanting to flex their engineering muscle, we’re taken aback by the sheer beauty of [Skot9000]’s huge LED display made of seven-segment displays. He calls the build DigitGrid, and it’s a wondrous display the likes of which we’ve never seen.

To build a display based on seven-segment LEDs, [Skot] went with a modular approach in designing the DigitGrid. To power and control all these seven-segment displays, [Skot] used a Texas Instruments TLC5920 to run four 4-digit displays as a single module. Four of these modules connect together to form a row of 32×2 digits, and eight rows of digits come together to make a 512-digit display. With seven LEDs for each digit, that works out to 3,584 4,096 individual LEDs for the entire panel.

To power and control this gigantic array of LED displays, each row uses a PIC16F microcontroller which, in turn, is controlled by an FPGA. After several hours of writing Verilog, [Skot] had a reasonably good hunk of software that allowed him to send frames from his computer to the display. The results, quite simply, are amazing. [Skot] managed to put up a short film showing off the animation capabilities of his new display, and it’s a wonder to behold. You can check that video out after the break.

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ATtiny44 Drop-in Replacement For Ikea Dioder’s Stock PIC Controller

March 28, 2012 by 7 Comments

The Ikea Dioder is an LED light sold at the big blue and yellow building that lets you mix your own colors using a simple button and wheel controller. [Marco Di Feo] looked at all of the other projects out there that alter the controller and figured out that the IC can be directly replaced with an ATtiny44 microcontroller. With that chip soldered onto the board he added IR control so that he can change colors using his universal remote control (translated).

[Marco] removed the potentiometer normally responsible for selecting the color. This frees up one pin on the microcontroller which he then uses to receive signals from a TSOP1736 IR receiver. The video after the break shows the device, which illuminates the back of his home entertainment center, reacting to commands from his remote control.

Of course this can be done without the chip swap as the PIC 16F684 that comes with it can be reprogrammed in place. But [Marco] didn’t have a PICkit or other programmer on hand. Continue reading “ATtiny44 Drop-in Replacement For Ikea Dioder’s Stock PIC Controller” →

Arduino Aquarium Lights

March 26, 2012 by 6 Comments

[Kalle Hyvönen] just finished building his own aquarium lights. He used four powerful soft-white LEDs, mounting them on a pair of heat sinks to keep things cool. Now he could have just connected them to the power supply and plugged it into the wall, but instead he included is own controller. An Arduino drives the switch-mode power supply, offering dimming thanks to PWM, and the ability to automatically switch the light on and off using an RTC chip with a battery backup. The sketch includes the ability to alter the lighting schedule and other variables by sending serial commands through a USB connection. This protocol is detailed with comments in his sketch.

We’ve seen a lot of interesting aquarium light projects. This one that uses heat from the LEDs to warm the water is one of our favorites. Others are full of features like this version that includes a moonlight mode. But Arduino enthusiasts don’t have to look far to find offerings like this PAR meter build, or this aquarium light controller library which can be recreated using the ubiquitous controller board.

Baby’s First Star Light Projector And A Foil Slip Ring

March 22, 2012 by 7 Comments

For a newborn, everything is magical; a lack of object permanence means everything is new, wonderful, and novel. What then, could be better than a projected star field circling an infant’s room, gently sending them to sleep?

[Pete] was inspired by this earlier starlight projector that projects a rotating star field onto the walls and ceiling of a nursery. Instead of a rather loud servo, [Pete] used a quiet 12 Volt gear motor that spins the star field at 5 RPM. Like the previous build, a LED was used but [Pete] found a color-changing RGB LED that automatically shifts colors.

The shaft of [Pete]’s gear motor is tiny, and unlike the servo, there’s constant rotation. This meant a slip ring was needed to pass electricity into the spinning sphere. A piece of copper foil and a pair of improvised brushes served just fine. While [Pete]’s project, like its predecessor, doesn’t seem to have any recognized constellations drilled into the sphere, the foil slip ring opens up the possibility for a small microcontroller being fitted inside the globe with blinking lights.

Check out the video of [Pete]’s build in action after the break.
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