Rainbow Board Of Many Ping-pong Balls

January 8, 2012 by Brian Benchoff 13 Comments

[George] just finished his first project: an 8×8 matrix “Board of Many Ping-Pong Balls” with 64 RGB LEDs. He started this project when he was 14 years old and finished the build over this last Christmas break. We won’t make any presumptions about [George]’s age, but we couldn’t think of a better project to start out on.

For the build, [George] used a Colorduino LED driver shield for his Arduino. This made the wiring simple, but the finished product is where this project really shines. For the base, [George] got a board laser cut at his school and used ping-pong balls to diffuse the LEDs. We’ve seen this many times but with this build there’s a neat way to drill a hole in a ping-pong ball; simply put the drill into reverse. The friction is enough to open the ball up, and the chips of plastic come outside instead of remaining in.

We’re really impressed with [George] and his winter break project. He’s lucky enough to have access to a laser cutter at school, and from a look at his monitor, he’s reading the right websites. You can check out his demo rainbow pattern after the break.

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Minimalist RGB LED Cube Has A Very Short BoM

January 7, 2012 by Mike Nathan 55 Comments

charlieplexed-led-cube

[Asher Glick] wrote in to share a project he has been working on with his friend [Kevin Baker], a 4x4x4 RGB LED cube. The pair are students at Rensselaer Polytechnic Institute and also members of the newly-formed Embedded Hardware Club on campus. As their first collaborative project, they decided to take on the ubiquitous LED cube, trimming down the component count to nothing more than 64 LEDs, a protoboard, some wire, and a single Arduino.

Many cubes we have seen use shift registers or decade counters to account for all the I/O required to drive so many LEDs. Their version of the cube has none of these extra components, solely relying on 16 of the Arduino’s I/O pins for control instead. You might notice something a bit different about the structure of their cube as well. Rather than using a grid of LEDs like we see in most Charlieplexed cubes, they constructed theirs using 16 LED “spires”, tucking the additional wiring underneath the board.

The result looks great, as you can see in the videos below. The cube looks pretty easy to build, and with a cost around $60 it is a reasonably cheap project as well.

Nice job, we look forward to seeing all sorts of fun projects from the Embedded Hardware Club in the future!

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Followup: Reproducing Impossible Circuits

January 6, 2012 by Brian Benchoff 43 Comments

Last month we caught wind of an impressive display of troll physics. [Fredzislaw100] out of Poland posted a video of a circuit that should not exist. As expected, the comments in our coverage blew up with 200 posts. About half the commenters called a little Adobe After Effects trickery, while the other half offered up an electrical explanation. We’re happy to report that [Alan] successfully reproduced the impossible circuit and earned an incredible amount of electronic wizard points in the process.

[Alan]’s solution uses low-frequency AC with the first two LEDs. The first LED points forwards and the second diode is reversed. Easy enough. For the third LED, [Alan] used high frequency AC with an inductor wired in parallel with the LED and the third switch. For those of you keeping track, that means [Fredzislaw100] put an SMD diode in two LEDs and two switches and an inductor in one LED and one switch.

[Alan]’s build is just a proof of concept – It’s still on a breadboard and doesn’t have the incredible level of polish that [Fredzislaw100]’s has. That being said, [Alan]’s build is most likely very similar given the small glitch at 2:05 in the original video.

Check out [Alan]’s build video below, and for an added treat check out his 2011 Advent Calendar of Circuits.

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LED Cube Is A Little Bit Of Kit, A Lot Of Point-to-point Soldering

January 5, 2012 by Mike Szczys 4 Comments

[Craig Lindley] recently finished building his own RGB LED cube project. It’s made up of four layers of 4×4 LED grids, but you may notice that the framework that supports the structure is not the usual ratsnet of wires we’ve come to expect. They’re actually long, thin circuit boards. [Craig] grabbed the Rainbow Cube kit sold by Seeed Studio for this project. But instead of pairing it with their Rainbowduino driver, he built his own to give him more options on how to control the blinky lights.

He’s using an Arduino Uno to control the display, choosing TLC5940 driver chips to safely provide the juice necessary to light up the grid. These drivers also offer 12-bit pulse-width modulation for easy color mixing. Driving the LEDs directly would have taken a large number of these expensive chips (over $4 a piece), but if multiplexed the design only calls for two of them.

Check out a video of the finished cube reacting to music thanks to the microphone and amplifier circuit [Craig] build into the driver board.

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Hackerspace Light Wall Plays Video At 30 Fps

January 1, 2012 by Mike Nathan 24 Comments

The folks at The Quad Cities Collaboration and Hackerspace (QC Co-Lab) were trying to find something to build for their first big project, and had to look no further than the wall for inspiration. The north end of their facility is home to a huge 15×17 glass block wall that happens to face a well-traveled roadway.

They decided that turning the wall into a huge LED display would be a great way to attract attention from passers-by, so they picked up some GE Color Effects lights and got down to business. Once they found out that the technical college next door was putting on an open house, the race was on to get the light display assembled as quickly as possible to maximize their exposure.

The team mounted the 255 LEDs in vacuum-formed reflective cones, which were attached to wooden frames before being installed behind the glass wall. An Arduino drives the entire display at a smooth 30 frames per second, a task they say tests the very limits of the board’s capabilities.

They finished the job in time for the open house, and as you can see in the video below, the display looks great.

Nice job QC-Co-Lab!

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Disco Icosahedron Rings In The New Year

December 31, 2011 by Brian Benchoff 2 Comments

While city engineers were setting up the multicolored ball of lights in Times Square this year, [Phil] at adafruit was busy designing the X2 Time Ball, a disco icosahedron perfect for celebrating the new year.

The ball is made of 20 acrylic triangles zip-tied together into an icosahedron. On each face, six RGB pixels light up via commands from an Arduino. The entire project is able to be controlled remotely thanks to the help of a pair of XBees. [Phil] whipped up a Processing sketch to control the LED ball any way we could possibly imagine.

Although it may be a little late to build an LED disco ball for this year’s New Year’s Eve party, that doesn’t mean we couldn’t use it the other 364 days of the year. It’s perfect for parties, weddings, and our weekly lightswitch raves. Check out the action video of the Time Ball after the break.

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Doomsday Keg Of Radness Helps Ring In The New Year

December 30, 2011 by Mike Nathan 3 Comments

doomsday-keg

Lots of people buy noise makers for New Year’s eve, others opt to sing Auld Lang Syne – then there’s these guys.

The crew at Stone Brewing Company throw an annual bash at their brewery in celebration of New Years, and while [Dino’s] countdown timer is great for intimate settings, they needed something bigger to wow the crowd. A busted half barrel was all the inspiration they needed to build the “Doomsday Keg of Radness”.

[Mike Palmer], the Creative Director at Stone handed the keg off to the maintenance crew for some remodeling, and got ready to fit it with all sorts of lights and other goodies. Holes drilled in the keg were fitted with bright pulsing LEDs, while additional LED light strips were laid out around the perimeter. The bottom was cut out to accommodate a Moonflower LED module, and a 24” monitor was strapped to the side in order to display a countdown timer. An old Macbook jammed inside the keg runs the video display, while the rest of the lighting is remotely controlled with an RF transmitter.

Now mind you this all went down last year, but since the display was such a hit, they will be busting it out again for the 2011 celebration.

Check out the short demo video below to get a look at the Doomsday Keg in action.

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