Wall-wart Retrofitted With A High-power LED Supply Circuit

February 13, 2013 by Mike Szczys 10 Comments

high-power-LED-wall-wart-supply

This custom circuit board picks up some of the pieces from a wall wart to drive a high-power LED. The basic concept is to keep the high-voltage components and swap out the low voltage ones for parts that will be able to drive the 10W load.

The PCB is custom designed, but you can see that it was shaped to match the wall wort’s original board. To the right is the original 500mA transformer. The low-voltage side uses an LM393 because of its dual-comparators. This provides feedback for both current and voltage and is a perfect compliment for the TOP242. We haven’t seen that part before, but [Mincior] says that it’s nice for this application as it has safety features that lock down the chip if power or temperature are above spec. Once the replacement is nestled inside of the plastic case it looks stock and makes sure that your custom LED fixtures will stand the test of time safely.

LED Tells You When Your Server Has Melted

February 11, 2013 by Brian Benchoff 37 Comments

LED

One of the benefits of writing for Hackaday is the ability to command at will a legion of readers to descend on unsuspecting web servers. Most of the time a server can handle the load of thousands of connections. On the rare occasion, though, a server is turned into a pile of slag and dross to the satisfaction of us here at Hackaday and to the ire of admins everywhere.

Checking to see if your server is still running or not isn’t terribly interesting, though. [Eric] thought it would be cool to have a proper physical visualization of how busy his server is, and ended up using a blink(1) USB-controllable LED to display his current server load.

The blink(1) is a small, USB controlled RGB LED that can be used as a universal indicator light. [Eric] had the idea of plugging it in to one of his servers and having the brightness of the LED change in response to the load on the server. He did this with a Python script that queries the Google Analytics API and returns a value from 0 to 255 in response to how popular his server was in the last 10 minutes.

Of course, there’s always a chance Hackaday could Slashdot his server. In that case, the blink(1) glows a steady red, alerting [Eric] to his popularity.

NASA Inspired Circadian Rhythm Lights

February 8, 2013 by Mike Szczys 10 Comments

circadian-rhythm-light-rig

After reading about an initiative between NASA and Boeing to develop lights for the International Space Station [Rasathus] decided to give it a go at building his own. The project uses RGB pixels to build a circadian rhythm light installation. Without the normal rise and fall of the sun the sleep wake schedule for the astronauts can be pretty rough. This uses color and intensity of light in a well-defined schedule to help alleviate that. [Rasathus] is trying to bring his project in well under the $11.1 million mark which was established for the ISS.

The light modules he’s using are from a strand of LEDs from Adafruit. Each is driven by a WS2801 controller, a common driver used for easy and complicated projects like this huge ball of light which our own [Jesse Congdon] tackled. The board above is the start of an adapter board for interfacing with the Raspberry Pi GPIO header. [Rasathus] wanted to make certain he didn’t fry the control electronics so he built some protection into this adapter. The control software is covered in the second portion of the write up. We’ve embedded the video from that post after the break.

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Wall Votive Display Controlled With A Glowing Cube

February 6, 2013 by Mike Szczys 6 Comments

wall-votive-display

This wall hanging would look great even if it did no more than light up. But thanks to a unique controller it’s meant to work as an interactive display for your living area.

The rectangles and votive candle cups are a set of three store-bought hangings. But lighting the candles and remembering to blow them out was a pain, so [Adiel Fernandez] decided to add the LEDs to make the job easier. But why stop at that, in addition to an RGB light for each cup he made them fully addressable. It’s all the better for a light show, but this also opens up the arena for all manner of different uses.

Accompanying the wall installation is a palm-sized cube meant to sit on the coffee table. Whichever side of the cube us up sets the function for the display, with a rotation tweaking the function, and a fast spin used as a select. If the power icon is on the side facing up, a fast spin will turn the display on or off. There are also functions for weather, temperature, transportation (we were thinking something like a bus schedule notifier but it’s actually a bit different) and animation patterns. After the break you can watch a demo of the cube functionality.

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Elemental Display Is Also A LED Wall

February 4, 2013 by Brian Benchoff 14 Comments

elements

[Dan] is an element collector, someone who gets his socks knocked off by bismuth crystals and the orange vapor of bromine. Of course every element collector needs a proper display case, and since the periodic table table idea is cliché, [Dan] decided to build an elemental display that’s also a really awesome LED wall.

The build started off as most do with a few sheets of plywood and 120 acrylic shelves for each item in [Dan]’s collection. The real magic happened when [Dan]’s buddy [Bill] was called in to make the display a little more interesting.

Behind each acrylic shelf is a three-LED section of a LED strip, each part of the periodic table having a different color. The 120 individual shelving units are broken down into 16-shelf groups, each driven by a custom LED driver board. These driver boards are connected to a master Arduino with phone cables and make wonderful use of a very neat TCL5940 Arduino library.

The elemental display has a few options; all-on, twinkling, an Apple ‘breathing’ mode, and a graphic eq, as shown in the video after the break.

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Infra Is A Television Made Of Infrared Pixels

January 31, 2013 by Mike Szczys 80 Comments

ir-television-using-625-tv-remotes

This television is perfect except for its low resolution and the fact that it can’t be seen by the naked eye. [Chris Shen’s] art installation, Infra, uses 625 television remotes as pixels for a TV screen. There’s a little bit of insight to be gained from the details which [Chris] shared with EMSL.

The remote controls were all throw-aways. Even if there are problems with the buttons, battery connectors, or cases, chances are the IR led in each was still functional. So [Chris] patched into them using about 500 meters of speaker wire.

Why 625 pixel? Because that’s how many LEDs the Peggy board can handle. We’ve seen this open source LED board driving video in other projects. Here it’s been connected to each remote using Molex connectors. Each of the headers has the same pitch as a through-hole 5mm LED. The entire board was filled with them, and a mating crimp connector terminates the end of the wire coming out of each remote. This makes setup quite easy as the remotes don’t have to be installed in any particular order as long as the physical location matches Peggy’s grid.

You can get a glimpse of the piece playing video in the clip after the break.

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7x7x7 LED Cube Driven By Arduino Mega

January 31, 2013 by Mike Szczys 16 Comments

Sure, the physical build itself looks great, but it’s what [Michael] did with the firmware that impresses us the most. He’s using an Arduino Mega to drive the 7x7x7 cube and manages to squeeze out what he calls 142 frames per second with the setup. We’re not sure FPS is the right measurement, as we believe it’s the multiplexing rate that he’s trying to describle. It takes 144 uS to scan the entire matrix once. He performs the scan seven times per frame and the result is a flicker-free appearance, even to cameras.

You can see a video demonstration after the break. Since [Michael] emailed us directly with more details about the build we’ve pasted those below the fold as well.

If you’re looking for a more entry-level Arduino LED cube this 4x4x4 project is just the thing.

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