About the Sensor Class Extension
To make it easier to write a device driver that exposes a sensor to Windows (and to the sensor and location platform in particular), Windows includes a sensor driver class extension, ISensorClassExtension interface. A required component for sensor device drivers, this COM object provides a simple set of interfaces that enable programmers to implement a sensor driver without writing lots of boilerplate code. Additionally, this class extension provides the following benefits:
Helps to ensure that user privacy is well protected because the class extension enforces appropriate access control restrictions for sensors that handle personal information.
Provides a standard way to retrieve data from the driver and to raise event notifications through the API layers.