PORTLAND, Ore. STMicroelectronics today (June 8) became the second company to field a pitch-and-yaw microelectromechanical system (MEMS)-based gyroscope, following a similar announcement in late April by InvenSense.
Geneva-based ST is betting that MEMS gyros will find a mass market in sophisticated user interfaces that enable the recognition of complex human gestures using angular momentum sensors for pitch, roll and yaw. Smart phones, gaming controllers and gesture-recognizing remote controls using MEMS gyroscopes are due in stores by Christmas 2009, according to the company.
MEMS acccelerometers have already been designed into such consumer items as the iPhone, a PS3 controller model and Wii "nunchucks," where they respectively measure tilt for switching the display from portrait to landscape mode, enhance virtual steering and allow free-style motion sensing. MEMS gyroscopes will add angular momentum (pitch, roll and yaw) to enable the recognition of more-complex human gestures.
"Gyroscopes are being designed into a wide variety of consumer electronics devices for [such functions as] image stabilization in cameras, gesture recognition in remote controls and games, and enhancing navigation systems," said Benedetto Vigna, general manager of ST's MEMS and Sensors unit. "In the past year, since announcing our first gyro, we have built a family of one- and two-axis MEMS gyroscopes that covers this range of applications."
Whereas accelerometers measure linear motion against the pull of gravity, gyroscopses measure angular momentum in a motion that is independent of gravity. Controlling an onscreen cursor with a gyroscope makes the cursor more responsive to user gestures. Gyroscopes can complement accelerometers in man-machine interfaces, remote-pointing applications, navigation and location apps (for example, enabling dead reckoning while indoors) and camera applications (to mitigate camera shake).
Pitch-and-roll gyroscopes are a good fit for image stabilization in cameras, while pitch-and-yaw gyroscopes are required for baton-like gaming controllers and for the new generation of remote controls.
InvenSense's gyroscope uses a disk-shaped actuator and a single-chip solution that bonds a CMOS wafer as the cap atop the MEMS wafer. ST's gyro uses a ring-shaped MEMS element on one chip and pairs that device with an application-specific IC that's wired bonded to the MEMS die in a single package.
"We are great believers in the two-chip MEMS solution," said Vigna. "Its cheaper to produce as well as quicker and easier to alter or enhance our designs."
ST's gyros measure from 30 to 60,000 degrees per second of angular momentum. A fourfold-amplification mode enables fine adjustments.