Coil Gun Speed Meter

October 1, 2009 by Caleb Kraft 28 Comments

_DIY_bullet_speed_meter (Custom)

One of the best parts of building a coil gun is seeing just how fast you can get that slug to move through the air. [Daniel] built this speed meter to be able to see exactly that. It is comprised of two optical sensors, one at each end of a barrel. As the projectile passes them, its speed is calculated using an Atmega16. Since the distance between the sensors is pre determined, its only some simple math to figure out the speed of an object passing between them. The result is then displayed on a nice looking blue LCD.

If the blue accent lighting and acrylic stylings look familiar, that’s because we’ve seen [Daniel] before. He’s the one that built the portable coil pistol.

[via HackedGadgets]

Build A Google-style Panorama Rig For $300

September 29, 2009 by Phil Burgess 24 Comments

PhotoTrail

As part of a “disruptive technologies” course at the United States Military Academy, [Roy D. Ragsdale] produced a working prototype of a Google Street View-like system called PhotoTrail. Like its corporate-backed inspiration, the system captures georeferenced 360-degree panoramas that can be viewed interactively in a web browser…but at a hardware cost of only around $300. [Ragsdale’s] prototype is based entirely on consumer-grade off-the-shelf components and open source software, all tied together by the yin and yang of DIY: foam core board and a few Python scripts.

This article from IEEE Spectrum magazine provides some background on the selection of parts and construction of the system, including a hardware shopping list and a list of links to all of the open source packages used.

The PhotoTrail prototype is surprisingly small and lightweight. A vehicle isn’t even required; the camera array can be carried overhead by a single person, making it possible to capture remote locations. But [Roy] expects future revisions to be even smaller and less obtrusive, perhaps mounted to a headband. Mount Everest awaits!

Capacitive Buttons Control All Life

September 28, 2009 by Mike Szczys 7 Comments

capacitive_game_of_life

Projects involving Conway’s Game of Life and utilizing a Nokia 3310 screen are quite popular with electronics hobbyists. [Droky] put these two together and went one step further by adding capacitive sensors to control the Game of Life. His work is a great example of how to use the Atmel QTouch capacitive sensor (QT100a datasheet). This chip does the heavy lifting that we’ve seen in other touch sensitive solutions. It operates from 2V-5.5V, requires only three capacitors and a resistor, has a one pin active high output, and sells for around $1 in low quantities. One thing [Droky] overlooked in his board layout is the ground pad on the bottom of the WSON6 chip. He was able to make it work by masking the trace that runs under the chip but you will want to alter the layout in your own designs.

If you’ve used the QT100a before we’d like to hear about your experience, and find out if button debounce handling is necessary with this chip. Let us know in the comments. You can see a video of it in action after the break.

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Ben Heck Gets Sloppy And We Love It

September 23, 2009 by Caleb Kraft 18 Comments

sc_7

[Ben Heck] is a name synonymous with game system hacking. His projects have been seen and praised by people all over the world for both their quality and their ingenuity. He’s so good, in fact, that many of his projects have gone far beyond what we typically think of as hacking. They look and feel like commercial products. While that is a fantastic accomplishment, we have a soft spot for seeing stuff that is truly hacked. This lasted job he did is a great example. The controller needed to work using a single hand, so he hacked it. He was in a hurry, so it didn’t get his usual professional finish. We kind of like it that way. This one handed controller mod can be seen in action after the break.

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Universal Credit Card In The Palm Of Your Hand

September 23, 2009 by Mike Szczys 38 Comments

universal_credit_card

Do you remember the magnetic card spoofer in Terminator 2? It was a bit farfetched because apparently the device could be swiped through a reader and magically come up with working account numbers and pin numbers. We’re getting close to that kind of magic with [Jaroslaw’s] card spoofer that is button-programmable.

Building off of a project that allows spoofing via an iPod and electromagnet, [Jaroslaw] wanted something that doesn’t require a computer to put together the card code. He accomplished this by interfacing a 16-button keyboard and a character LCD with an AVR ATmega168 microcontroller. Card codes can be entered with the buttons and verified on the LCD. Of course this is still dependent on you knowing the code in the first place.

As you know, credit cards use this technology. We don’t think Walmart is going to be OK with you pulling this out in the checkout line, not to mention local five-oh. This technology is also used for building access in Universities, businesses, and hotels. If used in conjunction with some other spy technology you’ll be on your way to becoming a secret-agent-man.

Hacking USB Serial Port Adapters

September 23, 2009 by Caleb Kraft 16 Comments

keyspan_all (Custom)

The folks at Openschemes.com have written up an article on how to convert a USB serial port adapter to a low voltage serial interface for interfacing with microcontrollers. Though you can always just buy one, this is a fairly quick and cheap solution, especially if you are in a pinch or don’t have access to a retailer. The specific models you should watch for, are the ones with two chips, a microcontroller and a line translater.They go through the process of finding exactly where to patch in to add an extra interface. It only takes a couple wires and you are ready to go.

Not only can you use this as your serial connection to another microcontroller, but you can actually take control of the one on the board itself. If you load it with the drivers from TI, you gain access to the flash memory and can do whatever you want. They don’t go into much detail here though, stating that they’ll write another article on that.

We thought this little bugger looked familiar so we went digging through our archives. Sure enough, we found this system in action back in January of 2008.

[via Hacked Gadgets]

Introduction To FTDI Bitbang Mode

September 22, 2009 by Phil Burgess 80 Comments

It was an interface that launched a thousand hacks. Near trivial to program, enough I/O lines for useful work, and sufficiently fast for a multitude of applications: homebrew logic analyzers, chip programmers, LCD interfaces and LED light shows, to name a few.

Today the parallel printer port is on the brink of extinction (and good riddance, some would say). Largely rendered obsolete by USB, few (if any) new peripherals even include a parallel connector, and today’s shrinking computers — nettops, netbooks, media center PCs — wouldn’t have space for it anyway. That’s great for tidy desks, but not so good if you enjoyed the dirt-cheap hacks that the legacy parallel port made possible.

Fear not, for there’s a viable USB alternative that can resurrect many of these classic hacks! And if you’ve done much work with Arduino, there’s a good chance it’s already lurking in your parts drawer.

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