LED Hacks

1891 Articles

Edge-lit Holiday Cards

December 10, 2008 by 8 Comments

edgelit

Got 30 minutes for a holiday project and don’t want to get wrangled into some sort of decoupage disaster? Evil Mad Scientist Laboratories can show you just how easy it is to do edge lighting effects. Pictured above are three holiday cards constructed using scored plastic. You can use many different types of clear plastic for this, not just acrylic. The lighting is just an LED on a coincell. Black tape is used to prevent light leaking from the edges. The red and green version above is two stacked layers. This looks like something fun to scale up for a larger project or just to kill some time.

LED Projector

December 6, 2008 by 6 Comments

led_projector

[PuffMag1cDrag0n] shows us how to make a fairly simple projected LED display. The projector is made from a 13×7 LED matrix and a couple fresnel lenses. The layout and construction is similar to the Lumenlab projector setup, only replacing all the lighting and LCD with an LED array. It communicates via serial port and is powered by a pic micro 16f648. We would love to see an RGB version of this. The directions are a bit rushed, but you should be able to get the gist. Just remember that you need some pretty powerful LEDs to throw a big image.

Controller Button Marquee

December 5, 2008 by 5 Comments

controller_marque

[Ben Heck] posted an interesting one-off project he built many months ago. Video game developer Infinity Ward approached him to build a large display that indicated what buttons on a controller were being pressed. They were planning on using it during player testing by recording the board and the monitor at the same time. They could then compare the two to see if there was any disconnect between the players input and the onscreen action. Infinity Ward is the developer behind games like Call of Duty 4.

[Ben] piggy-backed the switch connections and added an external port. He used a pair of octal buffer ICs to replicate the signals and activate the LEDs. The whole board is powered by the same 3.3V line that’s used by accessories like the chat pad. The triggers have three LEDs each and are lit using a resistor ladder. [Ben] comments that since this is a newer Xbox 360 controller, the active-low button scheme makes it fairly easy to work with. There is a video of the board embedded below. Continue reading “Controller Button Marquee” →

Working With Relays

December 5, 2008 by 24 Comments

relay

SparkFun’s latest tutorial shows you how to work with relays. A relay is an electrically operated switch. In this case, they’re using it to switch a 120V AC outlet. The article carries the standard warnings about how not to kill yourself with AC (plus some non sequitor linking throughout). As an extra precaution, they chose a GFI outlet. You probably know how a relay works, but it’s worth seeing how they implemented it. They use a transistor to prevent overloading the microcontroller’s GPIO pin. The control pin is pulled to ground to keep the relay off. A diode is placed across the relay coil to manage the power flow when it discharges. An indicator LED is included to show when the relay closes. This is a great foundation for an automation project, or maybe you just want to terrorize your cat.

Intro To Charlieplexing

December 3, 2008 by 4 Comments

charlie

[sixerdoodle] sent us this nice firefly project that serves as an intro to charlieplexing. We’ve mentioned charlieplexing before, in our LED Life post and the Breath Controlled LED candles post. This project is quite simple and focues mainly on how to make a charlieplexed circuit work.

The goal was to create a tiny firefly bottle with SMD LEDs and as few wires as possible. In the video, after the break, it is hard to tell just how small this thing is until we see the battery. There are clear directions and fantastic pictures detailing exactly how to set up a charlieplexed circuit with 6 LEDs.

Continue reading “Intro To Charlieplexing” →