Another Take On The Rear-window LED Marquee

January 9, 2013 by Mike Szczys 40 Comments

re-window-led-display

This rear-window LED marquee will help let the driver behind you know when you’re planing to change lanes or make a turn. But it also includes the ability to send a message like “Back Off!”. [Robert Dunn] was inspired to undertake the project after seeing the one we featured back in October. We’d say his has a better chance of being street legal since it uses all red LEDs.

The marquee is a matrix of 480 LEDs, all hand soldered to form the nearly transparent 48×10 grid shown above. This is important to preserve visibility out the back window of his truck. It makes us wonder about the feasibility of using SMD instead of through hole components. That would certainly make it even less visible when not illuminated, but the assembly process would be much more difficult. That’s because the 5mm LED packages fit nicely in the grid of holes he drilled in some plywood which served as the jig during soldering. The presence of leads also made the soldering process manageable.

Power to an Arduino board is provided from the cigarette lighter adapter. A set of six shift registers drive the columns while the rows are controlled by a 4017 decade counter and some transistors. Check out the blinker test video after the break to get a look at what this can do while on the road.

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Glass Delay Line Slide Used In An RGB Lamp

January 9, 2013 by Mike Szczys 15 Comments

glass-delay-lines-lamp

The spire used in this lamp is a part from an old television. It’s a glass delay line slide which pipes the light up from the Bluetooth controlled RGB lamp (translated) in the base.

We have looked at delay lines previously when [Dave Jones] tore down a camcorder to get at one. But we must have missed the EEVblog follow-up episode which explains how the glass slides work. The device uses physical distance to form a delay. Waves directed into the edge of the glass slide bounce around at an angle before being sensed at the collection point. [Lukas] liked the visual appearance of the part and decided to use it to add visual interest to his lamp project. The nature of the glass makes it perfect for directing the light up and away from the PCB.

The lamp consists of one RGB LED module controlled by an ATtiny2313 microcontroller. Also on board is a HC-05 Bluetooth module. This along with an app he wrote lets the user change lamp color and behavior wirelessly. You can see the lamp in action in the video after the break, but we think the camera shot probably doesn’t do it the justice it deserves.

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Morse Code Flower Is Trying To Tell You Something

January 2, 2013 by Mike Szczys 5 Comments

morse-code-flower

To the casual observer this flower looks nice as its illuminated center fades in and out. But there’s hidden meaning to that light. Some of the blinks are longer than others; this flower is using Morse Code.

[Renaud Schleck] wanted to try a few different things with his MSP430 microcontroller. He decided on an LED that looks like a flower as it will be a nice piece of decor to set around the home. To add the Morse Code message he wanted something a bit more eloquent (and less distracting) than purely digital flashing. So he took the dots and dashes of the hard-coded message and turned them into fading signals by using Pulse-Width Modulation.

He free-formed the circuit so that it, and the coin cell that powers it, would fit in the flower pot. A reed switch is responsible for turning the juice on and off. When placed near a magnet the flower begins its gentle playback.

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Color Changing Bag Matches Clothing Color, Tells You What’s Inside

January 2, 2013 by Mike Szczys 9 Comments

color-changing-shoulder-bag

Adding some lights to your everyday items will certainly give you a style leaning toward the world of Blade Runner. But if you can add functionality to control the blinky components you’ve actually got something. A great example of this is [Kathryn McElroy’s] Chameleon Bag. It’s a shoulder bag with a light-up flap. It can color match your clothing, but she also built some features that will let you know what is inside of the bag.

The project started by using a cardboard template in the size and shape of the bag’s flap. After adding an Arduino to control the LEDs and an RFID reader for an interactive element she sewed a replacement flap that also acts as a diffuser. In the video after the break she demonstrates matching the color of her scarf by reading a tag sewn in the end of it. She then starts loading up all the stuff needed for a day away from home. As the keys, phone, and computer are placed in the bag their tags are read, resulting in different combinations of color. Once everything she needs is inside, the flap turns green and she heads out the door.

This will go great with your illuminated umbrella.

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Three Conceptual Approaches To Driving A WS2811 LED Pixel

January 2, 2013 by Mike Szczys 21 Comments

[Cunning_Fellow] published a post with three proof-of-concept approaches to driving a WS2811 LED pixel. We looked at a project early in December that used an AVR microcontroller to drive the RGB package. [Cunning_Fellow] saw this, and even though he doesn’t have any of these parts on hand he still spent the time hammering out ways to overcome the timing issues involved with address the device. His motto is “put up or shut up” when it comes to criticizing projects featured on Hackaday. We love seeing someone pick up an idea and run with it.

The approach in all three cases aims to conserve clock cycles when timing the communications. This leaves the developer as many cycles as possible to perform other tasks than simply telling the lights what to do. One approach is an assembly routine that is just a shade slower but groups all 14 free cycles into one block. The next looks at using external 7400 series hardware. The final technique is good old-fashioned bit banging.

[Photo Credit]

Animated Holiday Wreath From A String Of LED Lights

December 23, 2012 by Mike Szczys 5 Comments

[Dennis Adams’] wreath lights project looks pretty good. But he did some amazing coding to produce a whole set of interesting animated patterns that really seal the deal for the project. Don’t miss the video after the break where he shows off all of his hard work.

He started with a string individually addressable LEDs. These are the 12mm variety like what Adafruit sells (we’ve seen them popping up in a number of projects). To mount each pixel he tried a several different prototypes before settling on a ring that was 14″ in diameter. The design was laser cut from acrylic, with sets of staggered holes to host each ring of LEDs. The final touch was to add ping-pong balls to diffuse the light.

As we mentioned earlier, the light patterns really add the finishing touch to the project, but there is more functionality there too. [Dennis] rolled in the ability to monitor a Twitter feed with the wreath. When he gets a new tweet, a different animation will let him know about it.

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O Christmas Tree Of Digital Logic

December 19, 2012 by Brian Benchoff 9 Comments

tree

[Chris] over at PyroElectro is getting into the swing of the holidays with a LED Christmas tree build. Unlike the other electrical Christmas trees we’ve seen this holiday season, [Chris] designed his tree entirely with digital logic – no microcontrollers included.

The tree [Chris] constructed on a piece of perf board is a beautiful spiral arrangement of 64 green LEDs.While we’re sure getting all the LEDs soldered to the right height, [Chris] makes it look so easy to create 3D structures with circuits.

The LEDs are driven with a set of eight shift registers, themselves clocked by either a predictable 555 timer chip or a pseudo-random pattern generated with a circuit built from a few hex inverters. By setting the tree to the sequential mode, a pair of lights travel slowly down the spiral of the Christmas tree. If set to random mode, an random number of LEDs light up and walk down the array of LEDs.

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