Traffic Lights Tell You When Your Xbox Live Friends Are Gaming

It sounds like [Andrew] is trying to build a Pavlovian response into his behavior when it comes to online gaming. He wants to make sure he doesn’t miss out when all his friends are online, so he built this traffic signal to monitor Xbox Live activity. It will illuminate the lights, and drive the meters differently based on which of his friends are currently online. When the light’s green, he drops everything a grabs a controller.

The base of the light is a black project box. Inside you’ll find the Arduino compatible chip which drives the device mounted on a piece of protoboard. A WIZnet W5100 adds network connectivity at the low price of around $25. There is one problem with the setup. The API which [Andrew] found doesn’t use any authentication. This means that he can only see the public status of his friends; anyone who has set their online status set to private will always register as ‘online’. If you know of an existing Xbox Live API that would solve this issue we’d love to hear from you in the comments.

Build A POV Death Star, You Will

Building a Persistence of Vision globe is pretty awesome, but overlaying a Death Star pattern on the display takes it to the next level of geekery. Like us, [Jason] has wanted to build one of these for a long time. His success pushes us one step closer to taking the plunge and we hope it will inspire you to give it a shot too.

As he mentions in the beginning of his write up, the mechanical bits of these displays are really where the problems lie. Specifically, you need to find a way to transfer power to the spinning display. In this case use went with some DC motor brushes. These are replacement parts through which he drilled a hole to accept the metal axles on top and bottom. We hadn’t seen this technique before, but since motor brush replacements are easy to find and only cost a few bucks we’d say it’s a great idea.

The 24 blue LEDs that make up the display are all on one side of the PCB. They’re driven by an ATmega328 running the Arduino bootloader. [Jason] uses an FTDI adapter to program the chip. Don’t miss the video embedded after the break.

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Janus: The Gatekeeper

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[Piet] wrote in to tell us about his hack that allows for his front gate to be opened without a key. Unlike this hack that we featured in August, you don’t need a subway pass, just a good memory. As explained in his article (and the video after the break) if the proper sequence of doorbell rings is input, the gate unlocks itself.

For hardware a [mehduino] is used to take the doorbell input and decide whether or not the “secret knock” has been achieved. The door can be unlocked remotely via a button on the processor. Reprogramming the code is achieved by simply holding the program button while the code is entered on the “remote ringer” button.

Be sure to check out the video after the break to see this lock in action. The housing application may not be exactly what you expect. Also of interest, is that in true hacker fashion, the bare processor is hanging by a hook on his wall! Continue reading “Janus: The Gatekeeper”

Crystal Doorbell Helps Class Up The Joint

Even if you live in a dump this quick build will make your doorbell sound high-class. The new rig uses a crystal goblet to alert you of guests at the door. We suppose the room-silencing sound of flatware on a wine glass does make a great attention getter.

For [Tobias] the hardest part of the build was getting his wife to sign off on it. But he says the 1970’s era original was looking pretty shabby, which kind of made his argument for him. It took just two hours to develop and install the replacement. It uses a servo motor with an articulated striker to ping the glass which is hanging inverted between two pegs. The original AC transformer (which are most often 16V) was used to power the Arduino. He built a simple rectifier along with a big smoothing capacitor to make sure the Arduino doesn’t reset when voltage dips. Although it’s not mentioned in his comments, we’d bet the doorbell wire has been rerouted to connect directly to the Arduino, rather than remain patched into the power loop.

Don’t miss the clip after the break to hear how great this thing really does sound.

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Personal Energy Orb Prevents Your Life From Being Swallowed By The Internets

We love the Internet, but we are definitely guilty of losing track of the time we spend traipsing around our virtual haunts. This project will not only remind you to get out and exercise, it will cripple your digital experience if you don’t heed its colorful warning.

[Janko Hofmann] calls it the Personal Energy Orb. It’s really just an Arduino and an RGB LED. But as with most creations, the idea is what makes it great. The orb has a dock next to your computer. It tracks how much time you spend online, changing colors as you rack up the hours. If you don’t heed the warning signs of overuse it will even start to slow down your mouse cursor. But never fear. Full functionality can be restored by topping off your personal energy. As you can see above, there’s also a docking station on [Janko’s] bicycle. The orb monitors your mileage, moving out of the red zone so that your computer will be unencumbered the next time you sit down for a long session of flash games. Don’t miss his video presentation embedded after the break.

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Wii Nunchuck Controlled Robot Exhibits Rock Solid Balancing

[Willy Wampa] is showing off his self-balancing robot. What strikes us about the build is how well tuned his feedback loop seems to be. In the video after the break you will see that there is absolutely no visible oscillation used to keep its balance.

The parts used are quite easy to obtain. The acrylic mounting plates are his wife’s design and were custom cut through the Pololu service. They were also the source of the gear motors. He’s using a SparkFun IMU with an Arduino and a motor shield. He first posted about the build about a month ago, but the new revision switches to a Pololu motor driver shield which he says works much better, and adds control via a wireless Wii Nunchuck.

The PID loop which gives it that remarkably solid upright stance is from a library written by [Brett Beauregard]. Once again the concept of open source lets us build great things by standing on the shoulders of others.

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Speech Recognition On An Arduino

Speech recognition is usually the purview of fairly high-powered computers chugging along at hundreds of Megahertz with megabytes of RAM. Bringing speech recognition to the low-power microcontroller you’d find in an Arduino sounds like the work of a mad scientist or Ph.D. candidate, but that’s exactly what [Arjo Chakravarty] did. He developed the μSpeech library for the Arduino to allow for speech recognition for a limited set of voice commands.

Where most speech recognition systems use FFT and very fancy math to determine what phonemes a user is saying, [Arjo]’s system does away with this unnecessary complexity in favor of using very, very basic integral and differential calculus.

From [Arjo]’s user guide for μSpeech (PDF warning) we can see it’s possible to connect a small microphone to the analog input of an Arduino and accept voice commands such as ‘left’, ‘right’, and ‘stop’. The accuracy is pretty good, as well – 80% if μSpeech is trying to recognize words, and 30-40% if μSpeech is programmed to recognize single phonemes.

Sadly we couldn’t find a demo video of μSpeech in action, but you’re more than welcome to grab it via github for your own project. Send us a video of μSpeech in action and we’ll put it up.