Fail Of The Week: Transparent Circuit Design Is Clearly A Challenge

October 9, 2014 by Kristina Panos 76 Comments

[Frank Zhao] wanted to try his hand at making a transparent circuit board. His plan was to etch the paths with a laser cutter and fill in the troughs with conductive ink. The grooves are ~0.1mm deep x ~0.8mm wide.

He used nickel ink, which is slightly cheaper than silver ink. The ink was among the least of his problems, though. At a measured resistance of several hundred ohms per inch, it was already a deal breaker since his circuit can’t function with a voltage drop above 0.3V. To make matters worse, the valleys are rough due to the motion of the laser cutter and don’t play well with the push-to-dispense nature of the pen’s tip. This caused some overflow that he couldn’t deal with elegantly since the ink also happens to melt acrylic.

[Frank] is going to have another go at it with copper foil and wider tracks. Do you think he would have fared better with silver ink and a different delivery method, like a transfer pipette? How about deeper grooves?

Fail of the Week is a Hackaday column which runs every Thursday. Help keep the fun rolling by writing about your past failures and sending us a link to the story — or sending in links to fail write ups you find in your Internet travels.

Laser Dog Goggles Make Halloween A Nice Night For A Walk

October 8, 2014 by Kristina Panos 31 Comments

Sure, you could dress your dog up for Halloween in some pre-fab hot dog costume or a little French maid outfit, but what’s the fun in that? Hilarious as it may be, there’s no hack there. [Becky Stern] will help you out of your pet costume rut with the tutorial for her latest creation, laser dog goggles.

First things first: the laser she uses is fairly benign. You can safely stare it down for just under 30 seconds, so your pet should be okay. [Becky] offers other helpful safety suggestions, like covering the delicate battery pack with fabric to avoid scratching damage, and waiting until the adhesives are completely dry before outfitting Rover. But hey, if your dog isn’t into eye wear, don’t force it.

These are based on Doggles brand dog goggles and the Adafruit Trinket. The laser is mounted on a micro servo so that it pivots back and forth, allowing your dog to scan the ground like RoboCop or Terminator. As you might expect, [Becky]’s tutorial includes a comprehensive list of tools and great documentation. Check out her video overview after the break.

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Scrobby’s On Your Roof, Cleaning Your Solar Panels

October 8, 2014 by Kristina Panos 33 Comments

Solar panels are a great, sustainable addition to your home’s energy scheme. They’re bound to get dirty, but they can’t withstand harsh chemicals and still be effective. While there are companies that will come out and clean your installation a few times a year, the service is a recurring cost that adds up quickly. With Scrobby, his entry into The Hackaday Prize, [Stefan] sought to build a highly affordable and sustainable solution that, after installation, requires no dangerous trips back up to the roof.

Scrobby is solar-powered and cleans using rainwater. The user can set and alter the cleaning schedule over Bluetooth from their phone. [Stefan]’s prototype was built around a Teensy 3.0, but he will ultimately use custom boards based on the Freescale KL26. In addition to the Bluetooth module, there are six ultrasonic sensors, rain and temperature sensors, and motor-driven spools for tethered movement.

Make the jump to see Scrobby get his prototype bristles installed and show off his abilities in [Stefan]’s demo video. To register for updates, check out Scrobby’s website. If you hurry, you can donate to Scrobby’s Kickstarter campaign. The question is, who will clean Scrobby’s solar panels?

This project is an official entry to The Hackaday Prize that sadly didn’t make the quarterfinal selection. It’s still a great project, and worthy of a Hackaday post on its own.

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Photography Rig Captures Holy Grail Shots

October 8, 2014 by Kristina Panos 6 Comments

You’ve seen amazing shots of water spouts and milk crowns. You’ve seen shots of bullets piercing glass ornaments, playing cards, and poor, defenseless pieces of fruit. Maybe you’ve even seen that holy grail of shots—a bullet piercing a water spout. But how is it done? How do photographers capture this two-headed mythical beast of high-speed photography? [Maurice] has cracked the code and shared it for all to see.

He uses a Camera Axe to trigger the camera, a device he came up with years ago that’s on its fifth version. His setup uses a 100mm macro lens, a key flash, and two fill flashes that sit behind a diffusing wall of whiteness. All three flashes are connected to a multi-flash board which feeds into Camera Axe. [Maurice] explains how he gets nice, tall water spouts by thickening it with xanthan gum. He adds Jet Dry to reduce the surface tension and some food coloring to keep things interesting.

[Maurice] also runs through his pellet shooting rig, which he made with some polyethylene tubing and an air compressor. He ended up shooting the pellets at 20psi, which sends them traveling at 75 feet per second. They move slowly enough that he can use his own stomach to stop them in the demonstration. Dialing in just the right settings to get the pellet to intersect the spout at the right time took some finagling, and that will hold true for anyone who attempts to recreate this setup. He gives a link to his code files in the video description to get you started. Video is after the break.

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Retrotechtacular: The Future’s So Bright, We’re Gonna Need Photochromic Windowpanes

October 7, 2014 by Kristina Panos 39 Comments

This is a day in the life of the Shaw family in the summer of 1999 as the Philco-Ford Corporation imagined it from the space-age optimism of 1967. It begins with Karen Shaw and her son, James. They’re at the beach, building a sand castle model of their modular, hexagonal house and discussing life. Ominous music plays as they return in flowing caftans to their car, a Ford Seatte-ite XXI with its doors carelessly left open. You might recognize Karen as Marj Dusay, who would later beam aboard the USS Enterprise and remove Spock’s brain.

The father, Mike Shaw, is an astrophysicist working to colonize Mars and to breed giant, hardy peaches in his spare time. He’s played by iconic American game show host Wink Martindale. Oddly enough, Wink’s first gig was hosting a Memphis-based children’s show called Mars Patrol. He went on to fame with classics such as Tic Tac Dough, Card Sharks, Password Plus, and Trivial Pursuit.

Mike calls up some pictures of the parent trees he’s using on a screen that’s connected to the family computer. While many of today’s families have such a device, this beast is almost sentient. We learn throughout the film that it micromanages the family within an inch of their lives by keeping tabs on their physiology, activities, financial matters, and in James’ case, education.

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Perceiving Invisible Forces With An EMF-Detecting Dress

October 3, 2014 by Kristina Panos 9 Comments

In June of 2014, [Afrdt] spent two weeks on a boat as an artist-in-residence in Linz, Austria. During that time, she created a dress that detects EMF waves and outputs them to vibration motors and a headphone jack.

[Afrdt] started by making two EMF coil antennas and sewed them to cuffs that snap together. She crafted fashionable fabric stripes that both conceal and carry the cables from the coils to an Adafruit FLORA that’s sewn into the body of the dress. The wearer experiences haptic feedback via vibration motors in the chest, and sonic feedback from a mini female headphone jack built into the collar. The zipper functions as a low-pass filter and volume control for the jack. One side bears resistive tape and runs to the FLORA, which is programmed to play an 800Hz tone. The other side runs to the headphone jack via conductive thread. As the zipper is opened, the pitch increases to toward the maximum pitch of 880Hz.

She drew inspiration for this project from [Aaron Alai]’s EMF detector project and built the code on top of it. Broader documentation and many more pictures are available both at [Afrdt]’s site and the residency program’s site.

This project is an official entry to The Hackaday Prize that sadly didn’t make the quarterfinal selection. It’s still a great project, and worthy of a Hackaday post on its own.

Transformer Inductive Coupling Simulation Is SFW

October 2, 2014 by Kristina Panos 12 Comments

[James] has a friend who teaches at the local community college. When this friend asked him to build a transformer coupling simulation, he was more than happy to oblige. Fortunately for us, he also made a video that explains what is happening while showing the output on a ‘scope.

For the simulation, [James] built primary and secondary coils using PVC pipe. The primary coil consists of 11 turns of 14AWG stranded wire with 4V ~~running through it~~ applied. The first secondary he demonstrates is similarly built, but has 13 turns. As you’ll see, the first coil induces ~1.5V in the second coil. [James] first couples it with the two windings going the same way, which results in the two 2Mhz waveforms being in phase with each other. When he inserts the secondary the other way, its waveform is out of phase with the primary’s.

His second secondary has the same diameter PVC core, but was wound with ~60 turns of much thinner wire—28AWG bell wire to be exact. This match-up induces 10V on the secondary coil from the 4V he put on the primary. [James]’ demonstration includes a brief Lissajous pattern near the end. If you don’t know enough about those, here’s a good demonstration of the basics coupled with an explanation of the mechanics behind them.

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