none
Sensor Hub “Magnetometer Accuracy” displays on Windows 8.1 SDT (Sensor Diagnostic Tool). RRS feed

  • Question

  • Hi,

    We are developing sensor hub interface on Windows 8.1, the interface is HID over I2C, based on “integrating-motion-and-orientation-sensors.docx” June 10, 2013 version, Windows 8.1 supports “Magnetometer Accuracy” feature, specification mentions,

    Sensor Platform Additions for Windows 8.1

    The following additions have been  made to Win32 Sensor Platform header files. They are also available in the Sensor Diagnostic Tool.

    // MagnetometerAccuracy: represents the runtime accuracy of the // magnetic field component of a sensor's data

    typedef enum MagnetometerAccuracy

    {

        MAGNETOMETER_ACCURACY_UNKNOWN = 0,

        MAGNETOMETER_ACCURACY_UNRELIABLE,

        MAGNETOMETER_ACCURACY_APPROXIMATE,

        MAGNETOMETER_ACCURACY_HIGH

    } MagnetometerAccuracy;

    As we add this data filed (magnetometer accuracy flag) into Compass sensor’s input report,

           HID_USAGE_SENSOR_DATA_ORIENTATION_MAGNETOMETER_ACCURACY,

           HID_LOGICAL_MIN_8(0),

           HID_LOGICAL_MAX_8(3),

           HID_REPORT_SIZE(8),

           HID_REPORT_COUNT(1),

           HID_INPUT(Data_Var_Abs),

    #define HID_USAGE_SENSOR_DATA_ORIENTATION_MAGNETOMETER_ACCURACY   0x0A,0x88,0x04

    After enumeration, Windows 8.1 is able to read correct Compass senor’s report descriptor, so, on Sensor Diagnostic Tool 0.7.2, SDT is able to add another magnetometer accuracy flag field under “HID Sensor Collection Compass”, and flag value can be updated (0~3) respectively via HID over I2C communication as sensor hub device updates this accuracy flag, but the problem is the data filed description on SDT is not displayed correctly, it showed “1637d8a2-4248-4275-865d-558de84aedfd.2”, suppose should be “Magnetometer Accuracy Flag” something like this.

    Please help to figure out the root cause? The SDT problem, or sensor hub device doesn’t transmit correct report descriptor to Windows 8.1?

    Thanks and Regards,

    Martin Yan

    Microchip Technology Inc.

    Tuesday, May 27, 2014 8:38 PM