LED Hacks

1919 Articles

Third Time’s A Charm – 512 LED Cube Kicks It Up A Notch With RGB LEDs

March 20, 2011 by 25 Comments

rgb_led_cube

In the comments section of our 512-LED cube post from the other day, several people suggested that to take the project up a notch, building a similar cube using RGB LEDS was the next logical step. It seems that Hack-a-Day reader [vespine] was way ahead of the curve, as he sent us the build details of his 8x8x8 RGB cube shortly after the other story was published.

His cube, which was finished earlier this year, uses 512 10mm RGB LEDs, arranged on top of a simple elevated stand. The stand conceals all of the circuitry he uses to control the cube, the centerpiece of which is a PIC32 MCU. A dozen TLC5940 16-channel PWM drivers are used alongside the PIC in order to adjust the color output of the LEDs, each of which can be addressed and colored individually.

The end result is just about as amazing as you would imagine. He has created several quick demonstration animations, which you can view in the video below. Be sure to stop by his site to see all of his build details – there’s quite a lot there.

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512 LED Cube (again)

March 18, 2011 by 37 Comments

We’ve seen LED cubes before, but [nick] upped the ante with his 8x8x8 LED cube that uses only three pins on his microcontroller.

Previous LED cubes we’ve covered drove the LEDs with shift registers and latches, but [nick] used STP16CP LED sink drivers to reduce the component count. The STP16CP can control 16 LEDs each, can be cascaded off of each other, and can operate up to 30Mhz. With a component like this, you’re limited by your microcontroller and not your patience or soldering skills.

While he was waiting for his LEDs to arrive in the mail, [nick] decided he would get a head start on the animation code by plunging into MATLAB. After getting an idea of what would look good on the cube, [nick] wrote the code on his PC to send commands to the arduino controlling the sink drivers. To wrap up the project, [nick] put the cube on a very attractive wooden box stuffed with the electronics. All tolled, a very efficient and elegant build.

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Tokyo Hackerspace Helping Disaster Victims

March 16, 2011 by 36 Comments

We, like the rest of the world, have watched in horror as footage of the recent earthquake-caused disaster has been reported from northern Japan. It’s easy to watch video and see nothing but distruction, however, life goes on and [Akiba] is looking for a way to help the recovery efforts. He mentions that one of the big needs in the disaster area right now is for light, as the power infrastructure has been heavily damaged. The mason jar seen above is a Kimono Lantern that was meant to accent a garden at night. It has a solar cell – one NiMH rechargeable battery – and one bright LED along with a charging circuit. It was designed in the Tokyo Hackerspace and they released the build files in hopes that a large number can be donated to those in need. With a reasonable amount of daylight, the single cell battery can be charged enough to provide 10 hours of light from the little device.

How can our hacks help others? That question has been on our minds for the last few days. Light is a great first step. But we’ve also wondered about information networks to help coordinate rescue and cleanup workers. There are hacks that bring WiFi using wind power or solar power. What other hacks do you think would be useful to aid in the recovery process?

PWM-controlled LED Display Is Truly A Gift From The Heart

March 16, 2011 by 7 Comments

led_heart_panel

Instructables user [Simon] admits he addicted to electronics. Lucky for him, his wife of 15 years is pretty cool with, or at least tolerant of his need to fiddle with anything that plugs in. As a gift for their wedding anniversary, he decided it would be neat to combine his love for his wife with his love for electronics. The result is the the RGB LED “Love Heart” you see above. He built an RGB LED circuit controlled by a PIC12F683 microcontroller, which shines into a hand-etched plexi-glass panel.

The LED color is controlled using PWM, as you would expect. What you might not expect however, is the lengths [Simon] would travel to ensure nearly perfect color and brightness matching across the 5 LEDs he used in his project. Since RGB LEDs do not have a uniform output brightness, he used a Lux meter to precisely measure the white balance of each LED. He then plotted the results in Excel before coding the PWM driver. Now that’s devotion! Once the LEDs were settled, he went about constructing the rest of the LED panel.

If you are interested in building one for your sweetheart, [Simon] has you covered – he provides all of the schematics, templates, and source code required to get the job done.

Continue reading to see a video of his heart panel in action.

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PICAXE Using LEDs To Communicate

March 15, 2011 by 16 Comments

[Relwin] has being working on using LEDs as bi-directional devices. The setup above allows him to use each LED as an input, looking for a bright light source and then syncing up with the activity it receives. It is the most basic of communications using the components. The hardware at the heart of the system is a PICAXE development board on the left. The blinking light to the right causes the LED on the left of the picture to blink, but moving the blinking source over to that side will reverse the effect. The chip is programmed to play a tune on a piezo buzzer whenever a connection is lost. What is interesting to us is that these green LEDs will not detect a red LED flashing because the voltage threshold is different on the detector side of things.

He’s got some code available, but we’re really looking for the ideas of what to do with this concept. Maybe something along the lines of LED matrix video puzzles, or a variation on this laser-pointer LED game. Watch the demo video after the break and then let us know what you would use it for by leaving a comment.

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ASync-Firefly

March 11, 2011 by 8 Comments

[dev_dsp] wanted to try his hand at creating a purely analog implementation of multiple synchronizing fireflies powered by a single battery and built from off-the shelf, through-hole components on inexpensive protoboard. In theory, even your local Radio Shack should still carry all of this stuff. He was obviously inspired by [alex]’s fireflies that we’ve covered in the past, but he wanted to see how far it could be taken without the use of a microprocessor.

In the end, [dev_dsp] relied on one crucial piece of digital ware, the ever-popular 555 timer IC, but he’s using analog discrete components to do the grunt work of adjusting the phase of each firefly by feeding a little extra current to the trigger capacitor whenever the flash of a nearby firefly is detected. After the jump, you’ll find schematics and a video demo of three ASync-Firefly modules in various stages of assembly playing with one another while [dev_dsp] discusses their operation.

Lol Shield Theatre Brings Online Video To The Pixelated Screen

March 11, 2011 by 4 Comments

lol_shield_theatre

[FallDeaf] bought a Lol Shield, and after making all sorts of blinky displays, he thought to himself, “What in the world can I use this thing for?”

In a really slick fusion of hardware, software, and the power of the Internet, he has created what he calls, “Lol Shield Theatre”.

The idea goes something like this:

You visit his site, and create your own “movie” by drawing on his virtual Lol Shield. Add as many frames as you would like, set the frame rate, then submit your creation. From there, you can download an Arduino sketch that contains your entire animation so you can play it on your own Lol Shield. You can also visit his Lol Shield gallery, where you have the ability to watch, download, and vote on movie submissions from other visitors.

He has also provided the source code to drive your Lol Shield, as well as created an API through which you can stream the various animation feeds from his Lol Shield gallery directly to your Arduino via a USB cable.

Be sure to check out the video demo we have embedded below, and show off your pixel cinematography skills over in the theatre.

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