[Jeri Ellsworth] has been working on a direct conversion receiver using an FPGA as an oscillator and a PC sound card DSP. Being the excellent presenter she is, she first goes through the history and theory of radio reception (fast forward to 1:30), before digging into the meat of the build (parts 2 and 3 are also available).
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[Jeri] threw down the geeky fashion gauntlet by building this LED enhanced dress. She chose to assemble the project for her trip to BarBot 2011, and we can’t think of a more appropriate setting for such a garment. It uses a motion sensor to set off a delayed pattern of blue lights hidden underneath the fabric.The best part of the hack is the instamatic camera. It looks like a fashion accessory, but it’s really hiding all of the circuitry for the lights.
Inside the camera a PIR sensor waits until it detects motion, sending a signal through an op-amp to the trigger circuitry. A 74LS14 Schmitt Trigger chip teams up with some resistor-capacitor timer circuits to build a delay chain for the LEDs. This way, after motion is detected the LEDs come on and off in a staggered pattern that doesn’t require a microcontroller and is very pleasing to the eye. See the Analog win for yourself after the break.
Back with another interesting vidoe, [Jeri Ellsworth] once again brings us an amusing and educational hack. This time she’s made a “shooting gallery” in the style of the old arcade games that actually used projectiles. In her version however, she’s using LEDs in the targets which are detected by the gun. In an effort to keep the feel the same, she rigged up a pinball bell to ding at the appropriate times and it is quite effective.
As usual, she does a great job of breaking everything down and explaining how it all works. She shows us around her prototype so you can see how it is constructed, if you can make it through the solder gun shootout in the beginning. If she were to continue with this project beyond the functional prototype stage, we’d love to see small video clips being displayed for the targets pepper’s ghost style. Maybe we’re just having fond memories of Time Traveler.
[Jeri Ellsworth] has been very excited about this new opportunity. She sent us a “pilot video“, so we’re assuming that there will be more to come. In the pilot, she explains how to build a musical art installation that will play music when a viewer is in position. She covers several different ways to detect the presence of the person, ultimately landing on using a PIR sensor for detection. We can’t wait to see where this show goes, but we hope she continues to do her own hacking videos as well.
A failed chemistry experiment led [Jeri Ellsworth] to discover a flexible substrate for electroluminescent displays. We’re familiar with EL displays on the back of a glass panel like you would find in an audio receiver, but after making a mesh from aluminum foil [Jeri] looked at using the porous metal to host phosphors. She starts by cleaning foil and using a vinyl sticker to resist etching portions of the aluminum. It then goes into a bath of boric acid, electrified with the foil as the anode. As the foil etches she tests the progress by shining a laser through the foil. After this the phosphors are applied to the back surface of the foil, covered in a dielectric, and topped off with a conductive ink that will carry the AC necessary to excite the phosphors. This is layering materials in reverse compared to her EL PCB experiments. See [Jeri] explain this herself in the clip after the break.
You can see above that this produces a pretty well-defined display area. It reminds us of that color changing paint display. We think it would be worth a try to build a few 7-segment displays using this method.
[Jeri] got her hands on some of the DuPont Luxprint EL ink and had some fun conducting experiments. She tried different materials for the base and the display itself. Not only does she just play with materials, she also tears apart a VFD and an LCD to see if she could use them for parts. The LCD turned out to be the most successful. We saw this stuff show up at the Bay Area Maker Faire and we’re excited to see it become more accessible.
[Jeri Ellsworth] made this silicon inverter at home, by hand. It took her two years to get the process figured out and achieve something we didn’t think was possible. The complexity of manufacture, and the wide range of tools and materials needed seem insurmountable but she did it anyway. Her home chip fab Flickr set is well commented and details her work area and part of the processing. If you’re hurting for more check out her 40 minute Metalab talk which we’ve embedded after the break.
If her name sounds familiar but you just can’t place it you may know her from The Fatman and Circuit Girl. We’ve also featured some of her hacks, such as her Pinball challenge against [Ben Heckendorn], and her giant Etch-a-Sketch.