LED Backlight Conversion Using Recycled CCFL Inverter Parts

March 4, 2011 by Mike Nathan 11 Comments

inverter_repair

[Ammon] repairs busted LCD monitors as a side hobby, so replacing burned out CCFLs and inverter circuits is something he can do in his sleep. One Dell monitor he received had him so perplexed, that he simply gave up on trying to repair the inverter circuit. He still wanted to get it working, so he had some narrow PCBs made and started working on his LED replacement backlight.

He built a driver board for the LEDs, populated with left over components that he stripped from the LCD panel’s inverter circuit. He needed space to insert his driver board, so he simply cut out a chunk of the inverter board and slipped his replacement driver board in its place. As you can see in the picture above, his board (in green) takes up far less space than the original inverter circuit it replaces.

He provides a schematic for his circuit as well as a PCB layout file, so it should be fairly easy to replicate his work. He has not posted schematics or layout information for his LED strips, but we’re betting he will if someone asks nicely.

Check out this pair of posts if you are interested in reading more about replacing your burned out CCFL with LEDs.

Arduino Based Ambient Lighting Improvements

March 3, 2011 by Mike Szczys 12 Comments

[Simon] improved upon an existing hack by making this Arduino ambient lighting system that has four different color regions. He was inspired by [Roy’s] processing-based setup which we saw a few weeks ago. That system used processing to determine the average color of the currently displayed image, then it displayed the color on a single RGB LED strip. [Simon] was thinking a little bit bigger.

He purchased a lighting strip that could be cut into different sections and then set out to develop his own software for multiple color regions. He had little or no experience with Processing so he went one abstraction layer lower and used Java to code his interface. It’s got a lot of nice settings where you can tweak how, when, and why colors are displayed. In the end he has four independently addressable color strip on the left, right, top-left, and top-right of the screen. The best part is that the Java suite he developed can be used on different platforms, having been already tested on Windows and Linux.

LED Artwork Disappears Right Before Your Eyes

March 2, 2011 by Mike Nathan 47 Comments

take_a_picture_demo

If you walked into an art gallery and saw nothing but blank canvases lining the wall, you might be compelled to demand your money back, or assume that you had discovered the world’s laziest artist. If this gallery happened to be displaying work by [Brad Blucher and Kyle Clements] however, you would be mistaken.

These two artists have collaborated to create a series of works titled, “Take a Picture“. Each picture they have built is constructed to look like an empty canvas when viewed with the naked eye. If you were to take a picture of the canvas with your cell phone or digital camera however, a whole new world would open up in front of your eyes. Their artwork is constructed using infrared LEDs, which cannot be seen with the naked eye, but are visible to nearly any CMOS or CCD sensor on the market. The images range from simple smiley faces and objects to abstract geometric shapes.

It’s a very simple, yet novel approach, and we happen to think it’s pretty cool. The artists have not said what they have planned for this project in the future, but we’d love to see it expanded using larger LED arrays to display higher-resolution images, or even short movies.

Keep reading to see how they went about creating these works of art as well as a promo video demonstrating the effect.

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How To Find WiFi: Carry A Big Stick And Use Long Exposures

March 2, 2011 by Mike Szczys 14 Comments

Here’s an artsy way to map out WiFi networks around you; use a big light pole and long exposures to graph them on top of photographs. This capture method is often called light painting, and uses the relative brightness of LEDs to stretch out a still image – moving the stick quickly while the shutter is open.

The four-meter tall rod used in this project plays host to 80 white LEDs. An Arduino along with a WiFi shield detect the relative signal strength of the network surrounding the device. The images that are produced with this method are quite pleasing and you’ll enjoy watching the video after the break. We just wish that there was some kind of Google Street View interface to share this data since someone had to go out pounding the pavement with the rather peculiar looking apparatus in order to gather the data in the first place.

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Bathroom Mirror HUD Displays Time And Weather

March 2, 2011 by Mike Nathan 18 Comments

By and large, the standard household mirror is one item that has not made much real progress over the years. They hang on the wall reflecting light, and that’s about it.

A few years back, some students studying in the Department of Interaction Design at Chalmers University sought to enhance their morning routine with an interactive mirror. Their project was constructed using a two-way mirror with several Arduino-driven LED displays embedded behind the glass. Once a hand is swiped past the pair of embedded light dependent resistors, the display is activated. Subsequent hand swipes trigger the mirror to toggle between the different modes, providing the user with the current time, weather information as well as a toothbrush timer.

The project writeup is quite thorough, including plenty of source code and information on some of the components they used. You can take a look at their work here (PDF).

Check out the interactive mirror we featured that served as inspiration for their project.

[Thanks Emil]

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Old School LED Light Show

March 1, 2011 by Mike Nathan 20 Comments

programmable_lightshow

Building LED arrays that can display all sorts of different patterns is pretty easy these days. Hook up an Arduino, do some charlieplexing, and off you go. When [Viktor] was younger he didn’t have all those fancy schmancy microcontrollers and circuit simulation software you kids have these days. In fact, last we heard, he had to walk to school uphill both ways – in the snow.

That didn’t stop him from building this gem of a project back in 1987. His LED chaser/light show does not use any microcontrollers at all, rather it relies on an EPROM to store predefined display programs. A series of switches are installed on the front of the flasher, allowing him to easily switch between the programs, and a pot is mounted to the front of the device to control the speed of the LEDs.

His light show is pretty slick, even for a project built over 20 years ago. Sometimes you just can’t beat a good, old-school hack.

Continue reading for a video demonstration of [Viktor’s] programmable light show.

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Endless Fun With LED Dominoes

March 1, 2011 by Mike Nathan 46 Comments

le_dominoux

Toppling dominoes is great fun for about 30 seconds at a time, when you are not busy setting them up for another run. [Randy] thought it was about time they got an electronic makeover to allow for constant, immediate gratification. Armed with a few simple electronic components, he has created Le Dominoux.

These LED-based electronic dominoes are actually quite simple to build. Each basic Le Dominoux is constructed on a small square of protoboard and consists of either a photo cell or phototransistor, a 555 timer, and an LED, all powered by a coin cell battery. The 555 timer, which is configured as a one-shot, is triggered when the photosensitive component on the back side of the domino is exposed to a bright enough light. The LED on the front end of the domino is then illuminated one time. This process is the electronic equivalent of a single domino toppling over.

He has constructed several variants of the Le Dominoux to act as flashing triggers, for outputting sound, as well as for turning tight corners. These variants allow the dominoes to be configured in many different ways, creating self-sustaining light shows. If anyone is looking for a fun project to introduce kids to electronics, this would definitely be it. Stick around to see a video of Le Dominoux in action – we bet you can’t stop watching it.

This is of course [Randy’s] entry in the 555 Design Contest, which ends tonight at midnight EST.

[Thanks Jeri]

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