Tuesday, April 26, 2011

Gyroscope - iPhone

While the entire world was giddily anticipating the start of World Cup soccer this year, it was nose to the grindstone here at Sourcebits developing new soccer madness updates of Funbooth for Mac and iPhone.  Work notwithstanding, our development team had serious fun during production of these applications.  Throughout the beta testing and QA we were constantly capturing images of ourselves in the props of the teams we support, and we made the most of the new social features with the on-the-fly uploading to Facebook and Twitter.  And at the same time, our gaming wing guys at Wandake were busy putting the finishing touches on their now-huge hit Wake Up the Box! for iPhone and iPad.  So it was a real party at times.

While all this was going on, of course there was some big news on June 7, when Steve Jobs introduced yet another Apple engineering marvel: iPhone 4.  Bundled with new features like front-facing camera, superior rear camera, dual mikes for increased noise cancellation, eye-popping Retina Display, multitasking, 720p HD video recording and even a new kind of gyroscope technology, iPhone 4 is a huge evolutionary step in smartphone design.  As the tag line says: “This changes everything.  Again.”  And, marketing hyperbole aside, as far as day-to-day use is concerned for sure this will change the way we use iPhone.
Before this year’s launch, several leaked – or mislaid – iPhone 4 models made the rounds of the major tech blogs, complete with gory dissections and the standard tsunami of specu-babble.  But there was one stealth feature all the teardowns and pundits failed to even guess at: the gyroscope.  And on our side, as veteran iPhone developers, when Steve Jobs announced this during WWDC we were all pretty excited.  And while it still hasn’t gotten much attention in the press, this feature is a game changer in iPhone’s rivalry with Android and Symbian devices.

Apple’s been pioneering smartphone innovations since iPhone’s introduction in 2007 with many widely imitated micro-technologies, in particular the accelerometer.  The accelerometer is a type of sensor that detects changes in a device’s orientation, vibration, rotation or fall by detecting linear acceleration along one of the three X, Y and Z axes – that is: up/down, right/left, and front/back.

3-axis accelerometers enable features we by now take for granted in smartphones (and lately, too, in non-Apple branded consumer digital cameras, music players, and gaming peripherals).  For example, landscape/portrait orientation shifting, tilt for directional control in games and applications, and shake features for refreshing a webpage or shuffling a playlist.  The 1st generation of accelerometer – pre iPhone 4 – could measure only linear motion; it couldn’t sense direction on a compass or twisting motions or rotation, nor had any notion of gravity.

Then last year Apple added a magnetometer to the iPhone 3Gs, enabling it to sense magnetized direction relative to the Earth’s poles. And now, with the introduction of the gyro in iPhone 4, Apple once more ups the ante in spatial detection / orientation with a new sensor for detecting 3-axis angular acceleration around the X,Y and Z axes, enabling far more precise virtualization of pitch, yaw and roll on iPhone.
While detection of change in velocity has been possible for some time thanks to conventional accelerometer calculations in terms of linear acceleration, the gyroscope has been designed to detect angular acceleration, which will detect change in both velocity and direction at the same time.  iPhone 4’s gyroscope enables the sensing of even slight degrees of rotation while simultaneously rejecting linear movements and hand jitters – both still ably handled by accelerometer’s linear movement detection technology.
Combining the 3 axes of the gyroscope along with the 3 axes of the accelerometer now enables iPhone to recognize distance, speed and direction as it moves real-time through space. And thanks to the CoreMotion APIs in iOS, developers with the vision to make use of gyroscope data can access it freely, as some have already done.

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