Radar Gun Teardown

November 28, 2010 by Chris Nelson 30 Comments

[Jeri Ellsworth] is at it again, this time she takes apart a hot wheels speed gun and in the process she does a good job of explaining how radar can be used to measure speed. She also demonstrates a way to determine if an object is approaching or receding from the radar gun.

The Doppler shift is one way to remotely measure the speed of an object. It works by measuring the change in frequency of a wave after it strikes an object. Rather than measuring the Doppler shift of the returning wave most radar guns use the phase shift. The reason is that the frequency shift of a relativly slow object (60mph), to a relitivly high frequency signal(10GHz) is small (about 0.893Hz), where the phase shift varies based on the distance of the object. This is all just a stepping stone in her quest to build a crude TSA body scanner.

Epic Wooden Marble Run For Kids’ Room

November 27, 2010 by Mike Szczys 30 Comments

Some parents buy kinetic sculptures for their kids at art or craft fairs. Not [Steve Moseley], he turned his kids’ hovel into a sculpture by wrapping a marble run around the entire room. It’s big enough, with so many features that finding a banner image was a bit tough. After the break we’ve embedded a video where you’ll see a wagon wheel lifter, plenty of gravity-fed curves, loops, inclines, rockers, a stair-step lifter, and… well you get the idea.

Considering the scope of the project it was remarkably inexpensive; about $70 in wood, $40 for the glass marbles, and around $60 for everything else. We’re glad he shared his building methods with such verbosity. You’ll need a well-stocked shop. Fine work like this requires tools common for woodworkers, but we’d bet the band saw and oscillating spindle sander were a godsend.

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Playing Hacker With A Toy Vault

November 15, 2010 by Mike Szczys 22 Comments

[Thomas Cannon] created his own hacking game by adding some circuitry to this toy vault. The original toy uses the keypad to control a solenoid keeping the door shut. He kept the mechanical setup, but replaced the original circuit board with his own ATmega328 based internals. He also added a USB port to the front. The gist of the game is that you plug-in through USB to gain access to the vault’s terminal software. If you can make your way through the various levels of admin access the loot inside will be yours.

Girltech. Sugar Cubes. Monocrome LCD

November 15, 2010 by Greg R. Jacobs 13 Comments

We’ve seen these little toys called “sugar cubes” by GirlTech around for a while now. They are a toy block, with an LCD on the front and they respond to movement, button presses and they interact with each other if you stack them up. We’re just as curious as anyone else about their internals, but maybe not quite curious enough to rush out and buy one. Luckily, we don’t have to as [Joby] has done it for us and documented what he found. While it may be lacking in extreme detail, at least our curiosity is somewhat satiated.
We can see that it has a 16×16 LCD, an unknown chip hidden under an epoxy blob as usual. To determine what character is shown, you can bridge one of 4 spots on the PCB, though he has only managed to switch to a little ninja and a question mark. Does anyone have any brilliant ideas on a project for these?

Pulito: The LEGO Roomba

November 14, 2010 by James Munns 12 Comments

When [Dave] installed hardwood flooring in his house, he needed a solution to help automate the monotonous task of routine sweeping. Rather than go out and buy one of the many existing automated sweep robots out there, he decided to use his passion for LEGO Robotics to design and build a NXT based Swifferbot he calls Pulito. His version implements all the important features such as object avoidance using bump sensors, an IR beacon used to automatically return to the charging station, and a photoresistor to monitor the charge of the battery. [Dave] also includes a nifty LEGO sensor multiplexor, allowing him to save on I/O ports, which is almost worth sharing by itself.

Videos after the break.

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Gum Ball Maze Updated… Now With Robots!

November 11, 2010 by Mike Szczys 5 Comments

In what is surely becoming an ever-growing Rube Goldberg machine, [Dan] updated his gum ball dispenser to include a robot arm. We looked in on this human lab-rat experiment that rewards successful maze navigation with bubble-gum just about a year ago. As you can seen in the video after the break he’s added several new features to delight users. The original had a maze actuated by an accelerometer and that remains the same. But when the device fires up, the wooden ball is moved to the start of the maze by a Lynxmotion robotic arm. That arm is mounted on rails so it can also move to deliver the gum ball after a successful run. There’s also an anti-jamming feature that shakes the gum ball dispenser to ensure you don’t come up empty.

Whether playing chess or being controlled by a mouse the Lynxmotion has been quite popular lately. [Dan’s] solution uses a vacuum pump to grab onto the spheres (both wooden and gum), similar to the method used with the CNC pick and place from a while back.

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Monotron Openly Monophonic

November 10, 2010 by Joseph Thibodeau 17 Comments

Famous synth manufacturer Korg has released the schematics (get them here if you don’t like to fill out forms) for their wee little Monotron for all to see and use! This is great news for anyone looking to build up a synth from scratch or to circuit bend their existing monotron. The filter circuits alone would be fun to add to an existing electronics setup.

Granted there are already many examples of monotron mods out there, but that shouldn’t stop you from experimenting with your own variations. Now with the schematics you can make fundamental changes to the architecture of the synth all from the comfort of your own CAD software. Want more oscillators? Distortion? It’s all out there for you to explore. We’re very interested to see how far people will run with this. And big ups to Korg for recognizing the value of hacking!

[via Retrothing]

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