Electronic Design
Digital Magic: Waving Your Hands In The Tablet Age

Digital Magic: Waving Your Hands In The Tablet Age

These days, no one thinks twice if you’re walking down the street talking to yourself. But many people still think it’s odd when someone starts waving their fingers on a phone or tablet. Imagine what someone from even a couple decades ago would think, let alone a century ago.

Our everyday tools are magic. There was a lot of hand-waving along with smoke and mirrors at the 2011 International CES in Las Vegas in January, but there was some real magic going on if you knew where to look.

Over at Razer’s booth, the Sixense crew was showing off the Razer Hydra controllers (see the figure). Each gamer gets a pair of controllers that utilize a magnetic positioning system (see “Sixense Sensor Provides Real 3D Positioning”). A base station runs an Analog Devices DSP to compute absolute position and orientation, which is something the competition can’t do. The controllers are wired to keep costs down and eliminate the need for batteries.

The hand-waving came about while playing the forthcoming first-person puzzler, Portal 2. Players can make some objects grow and stretch using gestures while pressing buttons on the controllers. It makes sense when playing the game and viewing the feedback on an HDTV, but to a third party the gamer looks very strange.

Of course, the same can be said for Microsoft Xbox gamers using the Kinect, which uses a camera to track players. The resolution isn’t as good as the Sixense approach, but it works. A number of HDTV remote control systems at CES also used cameras to determine position and movement (see “The UWand Intuitive Remote”).

Touch Gesture Interfaces
Tablets were all the rage at the show, and more than a couple hundred demos were showing off how to control systems using cell phones and iPads. The process was “easy” from the demonstrator’s point of view. It was simply magic to the uninitiated.

Yes, the process is simple and usually quite efficient once the magic method is explained. Still, there can be quite a bit of complexity under the hood.

For example, I have a Toyota Prius with a remote keyless entry system. The key fob stays in your pocket. To unlock the door, you simply pull on the handle. The door stays locked if the fob isn’t nearby. The process uses wireless communication along with capacitive touch detection. Now imagine drawing on the driver’s window with a few fingers to perform some other function.

Magic Movie Moments
It’s fun to see how movies reflect our discoveries and confusion. They can be humorous, but humor often highlights annoying or painful episodes.

Anyone remember Lex’s outcry in Jurassic Park while a raptor is trying to get through a door to have lunch? “It’s a Unix system! I know this!” Lex exclaimed when seeing a Silicon Graphics workstation running 3D File System Navigator. Of course, it’s obvious how to navigate to the program that locks the door.

Who could forget Montgomery “Scotty” Scott, chief engineer for the Enterprise in the Star Trek series, when he has a run in with a Mac and a mouse in Star Trek IV: The Voyage Home? After trying to use the mouse as a microphone, he proceeds to bang out the formula for “transparent aluminum” using the keyboard.

These days, gesture and multitouch interfaces with large and often virtual screens are the norm in movies and television shows like CSI and NCIS. They aren’t far from fact, although these shows tend to push the limits when it comes to image improvements and hacking ability.

Of course, it isn’t magic. It’s science and engineering. The future is touch and gesture interfaces, but who will know the secrets to the magic?

Analog Devices



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