Visible Kitteh Project Keeps Mice Out Of The House

April 21, 2012 by Brian Benchoff 28 Comments

[Aaron] and his wife have a wonderful cat that likes to contribute to the household by bringing field mice, shrews, and voles into the house as a ‘present.’ Obviously, this leads blood, fur, and viscera staining the carpet, and chasing around mortally wounded rodents isn’t [Aaron]’s idea of fun. To stop the cat from bringing small mammals into the house, [Aaron] is now preventing the cat from entering the house when it has an animal in its mouth.

[Aaron]’s project is inspired by this facial recognition cat door that refuses entry of all cats holding a small rodent in their mouth. To get his system working, [Aaron] started researching object recognition and built an Android app using the OpenCV libraries. To detect if his cat has a rodent in his mouth, [Aaron] is using Harr cascades – a proven object detection system that will detect and differentiate between a cat and a cat plus mouse.

Right now, the project is only about half done. [Aaron] is currently training his object recognition system, a process that can take days. Still, anything that keeps mouse guts out of the carpet is an awesome project in our books.

Science And Engineering Festival Comes To DC

April 21, 2012 by Brian Benchoff 5 Comments

If you’re around the Washington, DC metro area next weekend, here’s something for you. It’s the USA Science and Engineering festival, and if you’ve ever wanted to talk to [Adam] and [Jamie] from Mythbusters, [Bill Nye], and several astronauts, this is where you should be next weekend.

This is the second USA Science and Engineering festival. The first festival, brought to bear because of an act of congress. The last festival was highly successful (and fun), so we can’t wait to see the reports from next weekend roll in. This time around, there will be scale models of the Orion Service Module, an F-22 cockpit Demonstrator, and a demonstion of an F-35 taking off vertically. Yep, Lockheed Martin is hosting this festival, but it’s still cool.

Even though the website makes it seem this festival is geared towards children, we’re sure we’d have a blast visiting. Here’s a solution: borrow a niece or nephew and show them what engineering can do.

We have to note you can also visit the NASA Goddard Space Flight Center while you’re in DC. It’s just a short Metro ride (with a bus transfer) from the convention center where the festival will be taking place. We highly recommend the tour of the facility. If anyone knows if you can see the space shuttles Discovery and Enterprise at the Udvar-Hazy center next weekend, drop us a line. We’ll amend our DC ‘look at cool stuff’ recommendations.

Tip ‘o the hat to [Paul] for sending this one in.

Using A Touch Sensor As A Telegraph Key

April 21, 2012 by Brian Benchoff 14 Comments

[Sebastian] is learning Morse code and CW radio, and of course he needed a telegraph key. Instead of using the terribly unergonomic paddle style key, he built a capacitive touch iambic key over the course of a few evenings.

An iambic key usually has two switches. When one switch is closed, it will transmit a ‘dit’. When the other switch is closed, it will transmit a ‘dah’. Instead of using mechanical paddles, [Sebastian] brought his iambic key into the 21st century by using a touch sensor. An ATtiny45 measures the time it takes for a single metal plate to fully charge. It’s the same idea behind the wonderful Arduino CapSense library.

This isn’t the first capacitive-touch iambic key we’ve seen; this little guy is just a pair of metal contacts and resistors that plug right into an Arduino. With an ATtiny45, [Sebastian]’s build is a full-blown iambic telegraph key that plugs right into his CW rig. You can check out the walk through of the project along with [Sebastian] trying out his iambic key after the break.

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Valve Scoops Up Bright Young Electrical Engineers

April 21, 2012 by Caleb Kraft 22 Comments

Several bright young engineers have been swiped up to work for Valve. Yes, that Valve, the game company. Amongst them are [Jeff Keyser] aka [Mighty ohm] and [Jeri Ellsworth], both names that we have seen on these pages many times. We’ve heard that Valve is a fun and very unique company to work for. Apparently there’s no solid hierarchy.

What we, and everyone else in the universe wants to know is what they are building! There were rumors and speculation of a game console that were quickly squashed. [Michael Abrash] let out some information in an interview that he was doing R&D into wearable computing. He also points out that he was not making a product. So, let the speculation begin!

We asked [Jeri] if this meant she couldn’t publish her own hacks anymore due to contractual agreements, but she said that she can still do them and has some cool stuff coming out soon.

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Chumby Is No Longer Selling Hardware

April 21, 2012 by Caleb Kraft 19 Comments

Hearing that Chumby will no longer be selling hardware makes us a little sad. We’ve seen this thing used for so many different things, like shooting people with missiles, spitting out composite video, web serving, stomping around bipedially, and being a 3g router. We knew it wouldn’t be long, since they actually stopped manufacturing last year, but we just couldn’t help but feel a tear come to our eye when it was officially announced. Let us all take a moment of silence.

Sparkfun Electronics Launches An Educational Site

April 21, 2012 by Caleb Kraft 8 Comments

Sparkfun Electronics has launched an educational web site with a full curriculum of classes being held at Sparkfun Headquarters. If you don’t live nearby, no problem. You can download the entire curriculum as well. It appears that they will have a tutorial section for those who prefer a per-project approach, but that area is still “coming soon”. We love to see people educating others. Good job Sparkfun, looking forward to seeing more content on there.

(Model) Helicopter Physics

April 20, 2012 by Jeremy Cook 32 Comments

If you’ve ever wondered how a helicopter is able to fly, or would just like to see some awesome RC piloting, the four videos after the break should be just the thing! Although the basic physics of how one works is explained in the last three, one would still be hard pressed to explain how [Carl] is able to fly his RC helo the way he does. The video has to be seen to be believed or even explained, but one of the simpler tricks involved taking off a few feet, doing a forward flip, and flying off backwards and upside-down!

As explained in detail in the other videos, a helicopter is controlled by something called a swash plate on the main rotor, which in short translates a linear action into a rotational one. The same thing is done with the tail rotor, but you’ll have to check out the videos after the break for a full explanation! Really ingenious that someone could come up with this analog control system to use before computers were available.

Of particular interest to physics geeks, an explanation of gyroscopic precession is given in the fourth video. Controlling a helicopter may not work exactly the way you thought!

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