A Resistor’s Fiery Death Used To Launch Fireworks

July 4, 2012 by Mike Szczys 62 Comments

Check out this control center which [Awesome0749] built for launching fireworks. From the looks of his stash he’s going to be doing quite a bit of celebrating. The control console is clean and offers some safety features, and he just upgraded to an interesting ignition technique.

He’s using CAT5 cable to connect to the fireworks. At the top of the enclosure you can just make out the edge of the almond-colored wall plates which offer three jacks each. The two keys on the controller must be turned on to power the device. There is also a safety toggle switch in the middle.

The ignition is cause by running 70 VDC through a 1/4 Watt 24 Ohm resistor. As you can see in the demo after the break this results in flames quite quickly. One other thing we saw in the demonstration is that only the LED for the button which is hooked up comes on when the system is armed. We didn’t see a schematic, but he must have wired this so the system checks for continuity to ensure there’s something wired to the business end of the button.

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Fifa Looks At Electronic Augmentation

July 4, 2012 by Mike Szczys 12 Comments

The [Fédération Internationale de Football Association] is joining the growing list of professional sports that is adopting technological means in an attempt to help the human referees. After a botched call in 2010 the organization called for a system that would work day or night, with 100% accuracy and the ability to report to the Refs in less than 1 second. The applicants have been weeded out and it comes down to two systems, both of which use a piece of personal hardware we’re quite familiar with. [Fe80], who sent in the tip, recognized the TI Chronos eZ430 watch in the image above.

The two systems both use the watch as an interface, but work very differently. The first, called GoalRef, uses a sensor suspended inside the ball. This detects a magnetic field made up by the goal posts. We’d guess it’s an inductance sensor that is triggered when it passes a coil in the goal posts (we didn’t find much in the way of technical info so please do your own speculation in the comments). The second system is very familiar. It’s the Hawkeye camera system used by the APT (Tennis) in all the major tournaments.

The Most Surprising Game Of Simon You’ve Every Played

July 4, 2012 by Mike Szczys 18 Comments

How does one take a game of Simon and make it extremely awesome? The folks at the North Street Labs — a Hackerspace in Portsmouth, Virginia — have found the secret and it’s all in the execution. They turned this chair-desk into a coin-operated Simon game that hides a huge surprise.

We suppose you should be able to guess the secret. Most coin-operated sidewalk attractions are rides, and so is this. As their Red Bull Creation entry the team built a base for the desk around a 2000 Watt floor buffer. These are the kind of things that you’d see a janitor in the 1980’s using to polish the tiles of your middle-school. This one just happens to shake the bejesus out of a player who makes a mistake. To help suck you into the game this won’t happen right away. You have to make it past at least four rounds before making the mistake.

The rest of the game is as expected. The playing area is nicely milled from a piece of wood with acrylic windows serving as the buttons. Apparently the biggest problem with that part of the build is finding a way to hold everything together despite the intense vibrations. See for yourself in the clip after the break.

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[RobB’s] House Has No Light Switches

July 4, 2012 by Mike Szczys 46 Comments

So [RobB] wanted to take out all the light switches in his house. His plan was to replace them with a system that could be operated from his smart phone. But his wife insisted that there still must be some way to control the lighting directly — we have to agree with her on that one. The solution was to develop a system that switches the lights via a touch sensor or by Bluetooth.

The touch part of the project is pretty easy. He coated the back of a blank outlet plate with tin foil and hooked it to a microcontroller with a couple of resistors. He’s using an ATtiny85, which can be programmed using Arduino sketches, so the software side is made easy by the CapSense Library. The chip also uses the software serial library to communicate with a Bluetooth module. You can see the result of both in the demo video after the break.

Of course you need to throw a relay in there to switch mains, and find a way to power the uC and Bluetooth module. [RobB] went with a tiny plug-in USB power converter and managed to fit everything in a single-gang switch.

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The Excitement Of Ice Fishing Now From Anywhere In The World

July 4, 2012 by Mike Szczys 2 Comments

Now you can experience the excitement felt for centuries by ice fisherman thanks to this cellular-capable tip-up.

For the uninitiated a little ice fishing primer may be in order. The majority of what you see above is a standard tip-up rig for ice fishing. Basically it lets you set many baited lines and just watch for a flag to pop up when one of them hooks a fish. Just drill a hole in the ice and drop the line through — the orange frame rests on the surface of the ice.

The add-on here is the grey box which is hiding an Xbee device. A magnet and reed switch (which can be found at the local hardware store) complete a circuit when the flag is down. But if the flag pops up the reed switch opens (or closes, we’re not sure which) and the Xbee sends an alert to a base station, which then converts that to a text message to push to your phone. As you guessed, there’s a video after the break.

Fun and convoluted. But not entirely useless. We’d suggest swapping the Xbee/cellular hardware for a cheap microcontroller/Bluetooth setup. This way you can knock back a few cold ones in the ice house while waiting for the wireless network to alert you via an SL4A script.

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Levitating Lightbulb Does It All With No Wires

July 3, 2012 by Mike Szczys 58 Comments

It would be really fun to do an entire hallway of these levitating wireless lights. This a project on which [Chris Rieger] has been working for about six months. It uses magnetic levitation and wireless power transfer to create a really neat LED oddity.

Levitation is managed by a permanent magnet on the light assembly and an electromagnetic coil hidden on the other side of the top panel for the enclosure. That coil uses 300 meters of 20 AWG wire. A hall effect sensor is used to provide feedback on the location of the light unit, allowing the current going to the coil to be adjusted in order to keep the light unit stationary. When working correctly this draws about 0.25A at 12V.

Wireless power transfer is facilitated by a single large hoop of wire driven with alternating current at 1 MHz. This part of the system pulls 0.5A at 12V, bringing the whole of the consumption in at around 9 Watts. Not too bad. Check out [Chris’] demo video embedded after the break.

A similar method of coupling levitation with power transfer was used to make this floating globe rotate.

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Ti Chronos Watch Controls Raspberry Pi

July 3, 2012 by Mike Szczys 9 Comments

[Mike Field] was working on interfacing his TI Chronos eZ430 watch with the Raspberry Pi. As things were going pretty well, he took a side-trip from his intended hack and implemented watch-based control for an RPi audio player.

It really comes as no surprise that this is possible, and even easy. After all, the RPi board has native USB capability for hosting the watch‘s RF dongle, and it’s running Linux which we know already works well with the Chronos platform. But we still love the thought of having automation controls strapped to our wrist!

mpg321 is the audio playback program used for this hack. It plays MP3 files using ALSA for sound, which does have a few hiccups on the RPi. [Mike] found workarounds and included them in the C program he uses to gather everything into one nice code package. Control depends on keypresses sent from the watch (meant for use with PowerPoint) which are translated by his code and pushed to the audio/mp3 programs.