Wireless Electricity

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[Eric Giler] has a talk available over at TED that discusses and demos delivering electricity without wires. Called WiTricity, these methods were developed by a team at MIT a few years ago who were working off of the concepts of Nicolai Tesla. The facts shared about our current energy delivery system are a bit shocking; we’ve spent over $1 trillion in infrastructure and produce more than 40 billion disposable batteries each year.

The demonstration in the video starts about 6:30 into it. At first we see a flat panel television powered wirelessly from about 6 feet away, then the T-Mobile G1 powered from the same distance. The thought of new TVs coming with WiFi and WiTricity standard would mean just hanging it on the wall with no cords to run. We can also image cellphones that have a battery only for backup purposes when you were not near a transmitter.

The power transfer occurs between two coils that resonate at the same frequency and only that frequency. This remind us a bit of Orson Scott Card’s fantasy communications device from the Ender’s Saga.

Tiny Light-seeking Robots

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[Alex] continues to delight us with his projects. His third-generation tiny Braitenberg vehicle, a light seeking robot, is a big improvement over its predecessor, the mini Braitenberg vehicle. He’s moved from an Arduino based design to using the AVR ATtiny25v, replaced the breadboard with a PCB, and reduced the parts count. We think it was a great idea to use shrink tubing to shield the back of the photo-resistors from ambient light. Don’t miss the video of these little guys chasing a flashlight beam after the break. Continue reading “Tiny Light-seeking Robots”

Apple TV With Boxee And More Update

atvusb-creator

In November, we covered installing Boxee on AppleTV using atv-usb-creator. [Danny] has written a tutorial on installing Boxee, XBMC, NitoTV, SSH access, and external USB hard drive support. His method installs most of the software via the USB patch stick, then uses the SSH support to enable the external drive and install NitoTV. The tutorial lists a Mac running OSX 10.4 or newer as a prerequisite but there is now a Windows version of atv-usb-creator. According to their Google Code page Linux support for this package is on the way.

[via AppleTV Hacks]

Tradewars 2002 Lives

Are you growing tired of playing all those high-framerate first person shooters? Perhaps you long for the days of blocky graphics and text-based play. You’re in luck because Tradewars 2002 is still around. Many of you will remember this 1980’s BBS based game, playing a limited number of turns per day in an effort to rule the galaxy.

The game may be around, but the way you play it has changed drastically. The advent of custom scripts that interface directly with the game system makes this more of a who can write a better script rather than who is better at the game. A hacker’s challenge if you will.  Continue reading “Tradewars 2002 Lives”

Interfacing A Digital Rotary Switch

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[hw640] has put together a well written and detail packed explanation of how to interface with a digital rotary switch. These digital opto encoders have just two outputs with four possible logic levels (00, 10, 11, 01). The relative position of the switch is insignificant but the direction of rotation is what matters.

The short and dirty: Each of the switch’s 2 output pins is attached to a pin change interrupt on the microcontroller. Every time the switch moves it generates either a rising edge or a falling edge on one of the two pins; both edges cause an interrupt. By checking which pin caused the interrupt, then comparing the logic levels of the two pins after that interrupt, we can determine the direction the switch was rotated.

Although this explanation uses a PIC and code written in PicBasic Pro the concepts are discussed in the abstract and would easily be adapted to an AVR or another microcontroller of your choice.

Ubuntu Repository Crash-course

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[Alan] has just posted an Ubuntu screencast that will take you through a crash course in the Ubuntu repositories. If you are new to Ubuntu this will give you a much better grasp on how software repositories are handled.

The different types of updates are discussed: Security updates fix bugs that cause a system vulnerability. Updates (generic) are for bug fixes that aren’t a security threat. Proposed updates are for testing before an update hits the ‘updates’ section. Finally, backports are updates from a newer version that have been ‘backported‘ so systems running older versions of Ubuntu can have the benefit of newer features and fixed bugs.

He also provides some tips on selecting package sources (main, universe, restricted, and multiverse), and choosing the fastest mirror to reduce download times. This screencast is just part one and we hope to see 3rd party repositories, personal package archives, and repository caching covered in future installments.

Fedora Rawhide Nightly Builds

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The devs over at the Fedora Project are hard at work on the development version: Rawhide. They’ve just setup automated nightly builds of the liveCD which can easily be downloaded and tested on a CD, DVD, USB drive, virtual machine, or separate partition.

Rawhide will be released as Fedora 12 upon completion.  With this version you have a choice of Gnome 2.28 or KDE 4.3 for your desktop.  There is also improved power management, expanded support for mobile broadband, easy bug reporting, and many more new or improved features. So roll up your sleeves, download last night’s build, and help test some open source software.

[via Download Squad]