21st Century Light Bulbs Using 3D Printer And Chemistry Equipment

January 22, 2013 by Mike Szczys 20 Comments

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[Andreas Hölldorfer] brings his light fixtures into this century by using a couple of modern technologies. The fixtures combine LED modules, 3D printed pieces, and laboratory glassware to give his room a unique look.

The glass enclosure is something he’s had on hand for quite some time but they never actually got used. There is an opening at one end which is meant to receive a stopper. He modeled one including holes for the wires and printed the piece with a 3D printer. Also fabricated in the same way is a bracket that is used for mounting the fixture to the wall. The blossom of components inside the glass are each made up of five LED modules. There’s no word on what he’s using for a power supply or how he managed the cable runs, but he did post an image of two of the fixtures installed in his living room.

Plastic Sword Detects WiFi-enabled Orcs

January 21, 2013 by Brian Benchoff 15 Comments

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For a few years now, [Jomegat] has been thinking about Sting, the sword wielded by [Bilbo Baggins] and later [Frodo] in The Hobbit and The Lord of the Rings. Sting glows blue whenever an orc is near. Assuming the Elvish magic created by Tolkien is in reality highly advanced Elvish technology, [Jomegat] figured out a way to make his plastic Sting detect WiFi-enabled orcs.

Since The Hobbit was released, toy stores have been flooded with related merchandise that included a wonderful toy version of everyone’s favorite orc killing weapon. The only problem was how to add orc sensors to this plastic Sting. [Jomegat] assumed all orcs carry a cell phone, and being the low creatures they are, would always have their WiFi turned on. [Jomegat] found a very inexpensive WiFi detector key chain that would sense these phone-carrying orcs and light up to alert our warrior to imminent danger.

After acquiring the materials crafted from Elvish ~~magic~~ technology, [Jomegat] opened up the plastic hilt of Sting and installed the WiFi detector. Now, whenever Sting senses the preferred wireless connection of the orc, the blade glows a bright blue.

[Jomegat] was eaten by a grue shortly after completing this project.

Little Sister’s Turn For Hobby Electronic Party Favors

January 15, 2013 by Mike Szczys 10 Comments

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[Ian Lee, Sr.] made something special for his daughter’s birthday party. It’s pretty common for girls of this age (this was her 5th birthday) to be enthralled with stories of princesses so he made a blinky princess wand for each party guest. The motivation came when she asked what special thing he was going to do for her celebration. You may remember seeing the LED badge kits that were featured at her brother’s party earlier this year. From the look of the party guests he surely satisfied her desire for a memorable party.

The project is very inexpensive, extremely easy to assemble, and might make a perfect kit for supervised Kindergarteners. It’s basically an LED throwie with a stick and a feather added. [Ian] used CR2032 batteries along with an LED and current limiting resistor to light things up. He clipped off one leg of the LED and replaced it by soldering the LED in place. The remaining leads were then pressed to either side of the coin cell and the whole thing was shoved into a slit cut in the end of a balloon rod. The whole thing was wrapped tightly in with a rubber band before being crowned with a ping pong ball. To trim it out he hot glued a feather at the base of the ball.

The only think that has us worried is what he’s going to do next year to top these parties.

Papercraft Dial Is The Slide-ruler Of Current Limiting Resistors

January 14, 2013 by Mike Szczys 33 Comments

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This paper dial makes selecting current limiting resistors a snap. [Giorgos Lazaridis] came up with the tool, which he describes in detail in the Worklog tab of his writeup. If you want one of your own he also posted a PDF which you can print, cut, and tack together.

At this point we can calculate resistor values for LED circuits without looking at reference material. But it wasn’t always like that. This wheel will be a fantastic tool for those just starting out in hobby electronics who are trying to grasp the theory behind lighting up a simple project. The outer wheel references the source voltage, with the inner being a gauge of forward voltage across the LED(s). Line those two values up and you can read the optimal resistor value in the window seen to the right. But wait, there’s more! As you can see in the video after the break the opposite face of the dial also includes a window which will tell you the power dissipation so that you may choose a properly rated resistor. Slick!

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Replacement Drivers For Old LED Signs

January 11, 2013 by Mike Szczys 17 Comments

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The LED signs sitting idle on the left are brought to life by an Arduino replacement driver shown to the right. The big one is made by Signature Electronic and used as an advertising display like you would see in front of a business. [Bob Davis] picked it up on eBay being sold as non-working. After some power supply repair he set to the task of driving them with his own hardware.

The images he shared give us a good look at the parts used on the sign. The display area is made up of a set of eight 8×5 pixel LED modules. Each module has a key and slot in the top and bottom to help align the rows properly when building a larger array. They use TPIC6B595 shift registers (the same ones seen in yesterday’s low-res gaming hack) and 74HCT138 decoders to multiplex the pixels. Most of this info is shared in the second part of his post.

He hasn’t quite gotten the larger sign to run properly. Each row displays the same data but one pixel lower than the last. If you’ve got some insight on why this is happening we’re sure he’d like to hear about it.

[via Dangerous Prototypes]

8×8 LED Matrix Pendant Sealed In A Block Of Epoxy

January 10, 2013 by Mike Szczys 26 Comments

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This is the back side of [Dmitry Grinberg’s] 8×8 LED matrix pendant. He had seen the other projects that used a 5×7 grid but wasn’t really satisfied with the figures that can be drawn in that confined area when each pixel has only the option of being on or off. His offering increases the drawing area and includes the ability to display each pixel at several different levels.

He’s using an ATmega328 microcontroller soldered directly to the pins on the back of the LED module. He mapped out the IO in his firmware to make the soldering as easy as possible. To protect the hardware he fashioned a mold around the edges of the LED package using duct tape. The tape held epoxy in place as it hardened, encasing the microcontroller and holding the power wires and ICSP header tightly.

After the break you can see about six seconds of the device in action. The four levels of brightness for each pixel really do make quite a difference!

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