iPhone 4 gyroscope X-rayed, likely to be added to future iPad

Two new looks at the gyroscope found in Apple's iPhone 4 offer a closer examination of the technology behind the motion sensor, as well as an indication that the feature will be added to a future revision of the iPad.

Empty iPad slot hints at future gyroscope

UBMTechInsights took a look inside Apple's new iPhone 4 and found it was made by STMicroelectronics. The three-axis MEMS gyroscope is made by the same company that produces the accelerometer found both the iPhone and iPad.

Steve Bitton, senior analyst with TechInsights, noted that there is an empty slot on the iPad motherboard, perfectly sized to fit the gyroscope found in the iPhone 4. It is also located next to the accelerometer, and within proximity of the application processor.

The discovery suggests that Apple originally planned to have a gyroscope in the iPad, released in April in the U.S., but ultimately decided to leave the sensor out of the first-generation hardware.

But the pin out on the iPad motherboard doesn't match the STMicroelectronics gyroscope found in the iPhone 4 — instead, Bitton said, it resembles a competing three-axis sensor made by InvenSense.

"When Apple's iPad first came out, the InvenSense gyro was the only three-axis digital gyro on the market, so Apple may have designed its board with that component in mind," the report said. "Indeed, Apple may have included it in the iPad initially, but may have ultimately decided against using it in either device."

iFixit offers a look inside the iPhone 4 gyroscope

iFixit has also conducted a closer look at the iPhone 4 gyroscope, with the help of Chipworks. It also revealed that the gyroscope is made by STMicroelectronics, labeled AGD1 2022 FP6AQ. The microelectromechanical system (MEMS) integrates electronic and mechanical components at a very small scale to measure the orientation of the device.

X-ray photos of the gyroscope found that it is nearly identifcal to the off-the-shelf STMicroelectronics L3G4200D model. It includes a "proof mass" that is displaced in X, Y and Z directions by Coriolis forces when a user rotates the phone. Another die found inside converts those capacitive signals into a digital form that can be interpreted by the iPhone 4.

The gyroscope allows for far more precise movements with the device. One of the first App Store offerings to demonstrate this capability is the game Eliminate:GunRange (iTunes link), a $0.99 title from ngmoco, Inc. The software allows users to conduct virtual target practice by aiming their onscreen gun with precise movements of the device, something that is only capable with the gyroscope found in the iPhone 4.

iFixit and Chiwporks also included a number of photos of other MEMS gyroscopes not found in the iPhone 4, in the interest of showing off their incredible microscopic designs.