Windows 8 Tablets Sport Snazzy Sensors

Tablets for Windows 8 are spanning the spectrum of power/cost, but all have the same basic sensor complement, according to Technology Showcase presenters at this month’s MEMS Executive Congress

(MEC) in Scottdale, Ariz). Makers of micro-electro-mechanical systems (MEMS) sensors such as accelerometers, gyroscopes and digital compasses gather at MEC annually to report on current events, which this year included presentations by Intel and Freescale on Windows 8 tablets using their chips at the MEC Technology Showcase.

Intel detailed how Windows 8 tablets utilize a wide range of its processor chips, from ultra-low power Atom “Clover Trail” processors designed especially for Windows 8 like the Acer Iconia Tab to the high-performance Intel Core processors with backward software compatibility with Windows 7, exemplified by Microsoft’s own Surface with Windows 8 Pro

The ultra-low power Intel Atom “Clover Trail” Z2760 processor, designed especially for Windows 8, powers the Acer Iconia Tab. SOURCE: Microsoft  

Windows 8: Sensor Heavy

Windows 8 tablets are studded with micro-electro-mechanical system (MEMS) sensors, which is why they were featured at MEC. In fact, nine MEMS sensors are required to achieve Windows 8 certification, including a three-axis accelerometer, a three-axis gyroscope and a three-axis digital compass (magnetometer), resulting in a requirement for sensors with nine degrees of freedom (9-DOF).

Windows 8 tablets with Intel processors typically use Intel’s own sensor hub micro-controller to polls all those MEMS sensors, fusing their data into a representation of user proximity and tablet orientation  (landscape/portrait), heading, velocity and acceleration. These MEMS sensor readings are used by everything from location-based services (locating the closest Starbucks, for instance) to drop-detection that shuts down a tablet before it hits the ground. 

Optimized for Low Power Devices

The Atom Z2760 uses Intel’s 32-nanometer process technology, which has been optimized for low-power mobile devices, giving Atom Z2760 powered tablets the best battery life-times, according to Foust. For instance, running Window 8 applications on a Lenovo ThinkPad Tablet 2 yields up to 10 hours of battery lifetime even when watching HD videos. Atom Z2740 based tablets can also weigh as little as 1.3 pounds and with a battery powered keyboard attached, achieve up to 18 hours of battery lifetime. 

Predictably, the Atom-powered consumer tablets enjoy the longest battery lifetimes — as long as three weeks in “connected stand-by” mode, maintaining an instant-on capability anytime the display or keyboard is touched, according to Intel Sensor Technologist, Kenneth Foust.

“With connected standby, users are able to have instant access to their device at a moments notice,” says Foust. “When they touch the screen or hit the power button, it comes up immediately already connected to the local WiFi hotspot.”

Windows 7 Covered Both Ways

Tablets powered by both Intel’s Atom and Core processors can run all their normal Windows 7 applications, as well as the host of new apps in the Microsoft Store. Intel’s Atom Z2760 features Intel’s Burst Technology, has dual-cores with each with dual Hyper-Threading Technology–for four threads total. For security, Atom supports Intel’s Secure Boot and firmware-based Intel Platform Trust Technology (PTT). Intel Core processor powered tablets, such as the Intel Core i5 Processor in Microsoft’s own Surface with Windows 8 Pro, provides additional features including BitLocker drive encryption, Remote Desktop, Active Directory, and Client Hyper-V. 

For tablets that do not require backward compatibility with Windows 7 software, ultra-low-cost designs can be made using ARM processors, such as Microsoft’s own Surface for Windows RT. At the Technology Showcase, Freescale Semiconductor showed how an Windows 8 tablet can also use its 12-axis Xtrinsic sensor platform to add three more degrees of freedom to its sensor complement.

 Xtrinsic sensor platform for Windows

“Freescale’s Xtrinsic sensor platform for Windows 8 provides a complete 12 degree-of-freedom solution for tablets, laptops and other mobile devices,” explains Michael Stanley, Manager, C&I Systems and Product Definition, Freescale Semiconductor. “Our support software and application notes also show designers how to fuse the data from all those sensors using a Freescale ColdFire+ micro-controller.”

Freescale holds that the additional three degrees of freedom offered by its Xtrinsic sensor platform for Windows 8 enable more reliable sensor readings by offering more situational awareness and by performing algorithmic cross checks. The demonstration showed how just one tiny circuit board, which Freescale supplies in a reference design, allows Windows 8 tablet designers to simultaneously add all 12 sensors–three-axis accelerometer, three-axis gyroscope, three-axis magnetometer, altimeter, thermometer, and ambient light sensor (12-DOF).