Building Your Own LED-based Home Lighting

September 3, 2012 by Mike Szczys 10 Comments

We see LEDs used in all kinds of projects but rarely does someone build a home lighting system from scratch with them. [Paulo Oliveira] decided to give the idea a try, included a fading power supply for the LEDs which he built himself. Here you can see the installation at full brightness, but his controller also offers a single lower setting.

We saw [Sprite_TM] use an RGB LED strip to light up his living room. [Paulo] went with individual LED modules instead, all the same color. They are Cree XM-L power LEDs so some thought needs to be put into heat dissipation. All six are mounted along an aluminum strip which serves as the heat sink. They’re wired in series and powered by an old laptop power supply. A PIC 12F683 uses PWM to dim the string via a MOSFET.

The control system for the two brightness levels uses the wall switch. When turned on, the LEDs fade in to full brightness. If you turn the switch off and back on before they are all the way on, the dimmed setting takes over. This was complicated by the capacitance of the PSU but [Paulo] solved that by adding a power resistor.

Simulating LED Cubes In Blender

September 3, 2012 by Brian Benchoff 8 Comments

[youtube=http://www.youtube.com/watch?v=bl-kvfJxYwM&w=470]

The Jyväskylä, Finland hackerspace hacklab-jlk was lucky enough to work on a public arts project for their home town. They had the opportunity to design, build, and install a trio of LED cubes in Jyväskylä’s central Church Park. As such a high-profile project, the hacklab-jlk team decided to take their time and ended up implementing a lot of very cool features for their LED cubes, including simulating the light show in Blender.

The LED cube is similar to all the other LED cube builds we’ve seen before; it’s an 8x8x8 cube controlled by an ATMega328. The Elovalo project, as it is called, is a trio of LED cubes – one using red LEDs, one using green LED, and a blue LED cube each mounted on a pedestal in a Jyväskylä park.

Because the Elovalo is a permanent installation, the team needed a way to verify new firmware for the LED cubes. They came up with a LED cube simulator for Blender that allows them to write a new display function in C and render either single frames or a full animation of the lighting pattern.

A very cool build, and nearly too awesome for a public arts project. We look forward to a video of the complete installation, but until then we’ll make do with the short preview video available after the break.

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Building A Driver For Absurdly High Power LEDs

August 30, 2012 by Brian Benchoff 26 Comments

A few years ago, the highest power LEDs you could buy capped out around three watts. Now, LED manufacturers are taking things to ridiculous power ratings with 30, 40, and even 90 watt LEDs. Getting these high-power LEDs are no longer a problem, but powering them certainly is. [Thomas] built a LED driver capable of powering these gigantic LEDs and creating a light show that is probably bright enough to cause bit of eye damage.

[Thomas]’ LED driver is based on Linear Technology’s LT3518 LED driver. This driver is part of a project to build a huge WiFi controlled RGB LED, so the driver has outputs for three separate LEDs capable of sourcing 700 mA each.

Because [Thomas] is dealing with crazy amounts of heat and power required to light up these huge LEDs, the driver board features a temperature sensor next to each LED driver. When the board gets too hot, the driver automatically shuts down, preventing bad things from happening.

You can check out a few pictures of [Thomas]’ LED driver over on the build page for his WiFi LED project. A truly awesome amount of lighting power here, that also makes it impossible to get a good picture of the board in operation.

10bitworks Shows Us How To Light Up A Synchronized Swarm Of LED Jellyfish

August 24, 2012 by Mike Nathan 2 Comments

10bitworks-led-tshirts

[Jeremy Zunker] from 10bitworks recently wrote in to share a cool build the group put together for the Luminaria 2012 festival which took place in March of this year. As you might have guessed, the fest is home to a wide array of light-themed projects, so the team at 10bitworks thought long and hard to come up with a design which would help them stand out from the other 79 featured artists.

At the core of their project is a t-shirt which features a deep-sea diver surrounded by swarm of jellyfish. Each of the jellyfish is backlit by an LED module, allowing the group to create intricate light patterns on the shirt.

10bitworks brought 8 shirts to the show, each fitted with a small control pack that contained a set of batteries and a Jeenode wireless board. A ninth Jeenode and a large antenna were used as the master control unit, sending signals to each of the t-shirts in order to synchronize the light display.

The final result turned out very nicely as you can see in the video below, where [Jeremy] walks through all of the project’s finer details.

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Cloning A Water-based Light Wall Project

August 22, 2012 by Brian Benchoff 25 Comments

A few weeks ago, we featured this water-based LED graffiti art installation that allows anyone to paint in light using only a bottle of water. When one of [Chris]’ friends saw the video of this build, he immediately asked him how it worked. One thing led to another, and now [Chris] and a few other members at the BUILDS hackerspace at Boston University are building their own water LED installation.

The basic premise of this build is allowing water to serve as a conductor between the anode and cathode of a LED. Without spraying or painting water on the circuit [Chris] whipped up, there is an infinite resistance between the two pins of the LED and current cannot flow. After applying water to the anode and cathode pads, a small amount of current is conducted through the water and the LED lights up.

Right now, [Chris] is working on a test board with different sizes of pads and spacing to get the best water graffiti LED effect for his future build. The plan is to build a single one-meter panel out of one hundred 10 cm x 10 cm boards connected together with jumpers.

All of [Chris]’ work is up on GitHub, and even though [Chris] hasn’t begun designing the production boards, it’s more than enough to get you started if you’d like your own water LED painting panel.

One Dimensional PONG Is A Great Use For LED Strips

August 22, 2012 by Brian Benchoff 15 Comments

[Jason] has had a five meter addressable RGB LED strip lying around for a while, and only recently came up with a good idea of what to use it for. He came up with One Dimensional PONG, and it looks like it’s a blast to play. Instead of moving a paddle up and down, [Jason]’s 1D PONG game requires the players to stomp on a switch to send the ball back to the other player.

The LED strip [Jason] used has an SPI interface, but needed to be PWM clocked to a microcontroller to operate. After whipping up an Arduino library for his LED strip, [Jason] built an ATMega328-based controller board and a pair of seven segment display boards to keep track of the score. There’s a technical overview in another one of [Jason]’s videos.

[Jason] will be taking his 1D PONG game to the Brighton Mini Maker Faire on September 8th. We’re sure his game will be very popular there, so if you see him, tell him Hackaday sent you.

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Lite Brites Fade, But LED Clocks Are Forever

August 21, 2012 by Mike Nathan 7 Comments

Ahh, the Lite Brite.

What could be more fun than pushing dozens of little plastic pegs through a piece of black paper in order to create a pixelated, though colorful image? Well, I can think of quite a few things more engaging than that, and luckily so can [Lonnie Honeycutt] over at MeanPC.

While contemplating what to build with a pile of LEDs, his daughter came into the room with her portable Lite Brite. He thought that the pegs she was using looked awfully similar to the LEDs on his desk, so he did some test fitting and was surprised to see that they fit almost perfectly.

[Lonnie] thought that the toy would make an excellent clock, and his daughter happily agreed to let Dad do some tinkering. A few hours, an Arduino, and some Charlieplexing later, he had a nice looking clock that his kids were sure to enjoy.

If you’re interested in seeing more about how constructed, be sure to check out his YouTube channel and Instructable, where he happily provides all of the build details.