Windows 8 Has Native Support for Sensors to Adjust Display Brightness

In a January 24, blog post, Microsoft looks at the details of supporting sensors in Windows 8. "The first thing we explored about sensors was how Windows 8 should use them at the system level, to adapt the PC to the environment while preserving battery life was automatic display brightness control, or what we call […]

In a January 24, blog post, Microsoft looks at the details of supporting sensors in Windows 8. "The first thing we explored about sensors was how Windows 8 should use them at the system level, to adapt the PC to the environment while preserving battery life was automatic display brightness control, or what we call "adaptive brightness" that first introduced in Windows 7 using ambient light sensors (ALS)," states Gavin Gear, author of the post and a PM on the Device Connectivity team.

You can see in the pictures below that adaptive brightness helps you see content on the screen more clearly (pic left), since the screen automatically gets brighter when the tablet enters a bright environment. And those using desktop PCs in a sunny room (see pic on right):

tablet PC with adaptive brightness in outdoor lightingtablet PC in harsh outdoor lighting without adaptive brightness

He said that Microsoft decided to support three different types of sensors for Windows 8: a 3D accelerometer, a 3D magnetometer, and a 3D gyro. All of these sensors will be used at once in what Microsoft calls sensor fusion:

"Using a combination of these sensors it is possible to create a better, more responsive, and more fluid experience than the sensors can provide individually," said Gavin.

Adding he notes "We helped minimize the power and performance impact for sensor fusion systems running on Windows 8 in two major ways:

  1. We architected the sensor fusion interfaces in Windows 8 to enable much of the processing of sensor fusion data to happen at the hardware level. This hardware-level sensor fusion capability means that computationally expensive algorithms don't have to run on the main CPU, saving power and CPU cycles.
  2. We implemented powerful filtering mechanisms that we tied directly to the needs of sensor apps running at any given point in time. This pay-for-play data and event model means that sensor data is only sent up the stack at the rate that apps need that data, and no faster. This results in greatly reduced CPU utilization for sensor data throughput."

Microsoft also provided hardware developers with a set of standards and also created a single driver that would work for all such hardware that used USB support.

"If you are wondering how you can try out sensor fusion on Windows 8, or even write some apps that use these new capabilities. Developers who attended the //build/ conference in 2011 received the Samsung Windows 8 Developer Preview slate PC, which included a full package of sensors," Gavin revealed.

Adding he said, "there were only about 4,000 of those given out, and now the same 9-axis sensor fusion system that was built into the Windows Developer Preview device is available online for purchase from ST Microelectronics."

"The "ST Microelectronics eMotion Development Board for Windows 8" (model # STEVAL-MKI119V1) attaches via USB, and works with the HID sensor class driver that's included in Windows 8," added Gavin.

Also, note that the coming Windows 8 beta looks to called as the "consumer preview." Windows Director of Consumer PR, Janelle Poole, called the coming Windows 8 beta "the consumer preview." Per her quote:

"We haven't talked about the release date and we generally don't. We are talking milestone to milestone, so for us right now we're talking about the next milestone being the consumer preview happening in late February."