At the Heart of the Wii, Micron-Size Machines

[RedEarth]

EVEN before its release last month, Nintendo’s latest video game console, the Wii, was getting a lot of attention for its wireless motion-sensitive controllers. Swing the controller and — crack! — hit a virtual home run in a virtual ballpark, for example.

One controller is shaped like a sleek television remote (sometimes called the Wii-mote); the other plugs into the remote with a short wire, creating a vague resemblance to the two-handled martial-arts weapon it is named for, the nunchuk.

And beneath the controllers’ white plastic shells are an array of time-tested digital technologies working together in new ways.

The controllers communicate with the Wii console, a $250 box no larger than a child’s lunchbox, with the wireless technology known as Bluetooth. It is the means commonly used to link cellphones with their wireless headsets. The Wii remote also uses infrared, the same technology that links television sets with their remote controllers, to track where the controller is pointed.

In this case, a sort of crude camera — an image sensor — in the forward tip of the remote (the primary controller) detects tiny light-emitting diodes in a “sensor bar” that must be set on or very near a television plugged into the Wii. This system helps players use the remote to point accurately at specific things on the screen, like the virtual buttons to begin or end a game, or aim a weapon in a game.

http://www.nytimes.com/2006/12/21/technology/21howw.html?pagewanted=print