The Band’s Name In Lights, RGB LEDs To Be Exact.

November 8, 2012 by 18 Comments

A few of [michu]’s friends formed a band named Kalikut Now and needed an awesome stage show. The band made a few 80cm-high letters of their band name, cut a few pieces of acrylic, and wired them up with a few LED modules. The work of connecting these letters to a computer and programming them fell on [michu], and we’ve got to say he did a pretty good job.

You may remember [michu] from his StripInvaders and PixelInvaders projects, basically a few RGB LED modules that can communicate with an Arduino over an SPI interface. With these huge letters, [michu] ran into a problem: he had 11 meters of cabling between the clock and data lines, far beyond the maximum recommended length for any datasheet.

[michu] looked around the Internet for common problems with SPI interfaces and found a lot of good advice from a lot of very smart people. The issue with the SPI bus was eventually solved by correctly wiring the grounds of his LED modules, building a few dead-simple SPI buffers, and reducing the clock speed of the SPI bus.

After countless hours, the band’s name is in lights, and RGB LEDs to boot. Everything can be controlled with Abelton Live, and looks absolutely fantastic as seen in the video after the break.

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Beginner Project: Color Sensing With RGB LEDs And A Photocell

November 5, 2012 by 16 Comments

I’ve seen the concept art for “real world eyedroppers” several times. I haven’t noticed any of the products come to market though. It isn’t the technology stoping them, color sampling can be done a million ways. I picked one of the easiest ways and tossed something together pretty quickly.

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Hacking A Floating RGB LED Decorative Ball

September 8, 2012 by 36 Comments

Knowing that I’m always happy to get something new and glowy, my wife brought home a cheap “floating pool light” that she found on sale for roughly $10. This is a large white floating ball that has LEDs inside and cycles through different colors. Meant to be put into a pool for neat effects, we found it to be much more interesting just used around the house.

However, it was a bit too bright and cycled colors too quickly for our taste. It was actually somewhat distracting when we were just trying to sit and have a few beers late at night on our patio. This gave me a perfect excuse to tear it apart and start hacking… like I wasn’t going to do that anyway.

What I found inside was extremely simple. There’s a single un-marked chip that holds the different display modes (there were 3 display modes: warm, cool, and white). The LEDs were arranged in an array of Reds, Blues, Greens, and Whites (half marked yellow).

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Time And Date Clock Does It With RGB LED Strips

May 17, 2012 by 1 Comment

[Craig’s] color clock really came together quite nicely. The majority of the body is acrylic, with two large clear squares and a pair of colored discs. All are held in place by a ring of hardware with spacers in them, and the RGB LED strip that is used to display time and date wraps around those spacers. This hides the components in the center, with a USB cord connecting to the Arduino compatible board to power the device.

Hours are displayed in red, with minutes shown in green, and blue used as a background color. In the center you can see one of two red LEDs which alternate like a pendulum to mark the passing seconds. There are timed events every ten , fifteen, and thirty minute. At the fifteen minute mark the clock switches to display the date. The other two events are animations to keep things interesting. All of the settings for the clock are accessed using just two momentary push buttons mounted on the back of the clock.

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Reverse Engineering An RGB LED Remote

May 10, 2012 by 30 Comments

In the quest to add some mood lighting in his basement, [Mohonri] found an infrared wireless remote that is able to control several RGB LED strips. The only problem with this remote is the inability to control it via a wall-mount panel or even a computer. Obviously this would not stand for such a swank basement, so [Mohonri] did the reasonable thing and reverse engineered one of these remotes.

The build started with ripping the remote apart and figuring out how it ticks. [Mohonri] found the small IR LED transmitter and hooked up an oscilloscope to capture some data. After a bunch of trial and error and a big help from relevant documentation he had the entire button matrix – and thus the functions available to the LED strip – available to output via wall panel or computer.

[Mohonri] hasn’t completed his build yet; this was just the reverse engineering and documentation stage. Now, though, it shouldn’t be hard to control the RGB LED strips through an Arduino, a computer, or even an Android/iOS device with a small IR LED plugged into the headphone jack.

Minimalist RGB LED Cube Has A Very Short BoM

January 7, 2012 by 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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Color Sensing With An RGB LED And Photoresistor

December 8, 2011 by 11 Comments

[Fjord Carver] brings together an RGB LED and CdS Photoresistor to make a color sensor. Those Cadmium Sulfide lights sensors usually have a very wide swing of resistance when exposed to varying levels of light sensitivity. That makes for great resolution when reading them using the ADC of a microcontroller. The LED comes into play by shining known wavelengths of light on the surface being measured. Three separate readings are taken with each of the LED’s different colors, then used to extrapolate the RGB value of the test material. We saw the very same method used a couple of years back. This time around it’s an Arduino doing the measuring instead of a PIC.

So why isn’t that sensor shown in this picture? It’s because we appreciate the application which [Fjord] is using for this sensor. He built a lamp that shines the same color as the surface on which it is placed.