Windows UWP Sensors API Reference

Orientation Sensor (LSensor)

The Orientation Sensor (Windows.Devices.Sensors.OrientationSensor) is used to determine the orientation of the device in 3D space. It provides data about the device's rotation around the X, Y, and Z axes.

Overview

The Orientation Sensor is a composite sensor that typically combines data from the accelerometer, gyroscope, and magnetometer to provide a more accurate and stable reading of the device's orientation. This sensor is crucial for applications that require precise knowledge of the device's tilt, roll, and yaw, such as augmented reality, gaming, and navigation.

Properties

Methods

Events

Reading Data

The OrientationSensorReading object provides the following properties:

• Quaternion: Represents the orientation as a quaternion.
• RotationMatrix: Represents the orientation as a 3x3 rotation matrix.
• YawPitchRollAccuracy: Indicates the accuracy of the yaw, pitch, and roll values.
• Timestamp: The time at which the sensor reading was taken.

Usage Example

Here's a C# example of how to use the Orientation Sensor:

using Windows.Devices.Sensors;
using Windows.UI.Core;
using System;

// ...

public sealed partial class MainPage : Page
{
    private OrientationSensor _orientationSensor;
    private System.Text.StringBuilder _sb;

    public MainPage()
    {
        this.InitializeComponent();
        InitializeOrientationSensor();
    }

    private void InitializeOrientationSensor()
    {
        _orientationSensor = OrientationSensor.GetDefault();
        _sb = new System.Text.StringBuilder();

        if (_orientationSensor != null)
        {
            // Set the desired report interval
            uint defaultReportInterval = _orientationSensor.MinimumReportInterval;
            uint fastReportInterval = Math.Max(defaultReportInterval, 16); // Aim for ~60 FPS
            _orientationSensor.ReportInterval = fastReportInterval;

            // Subscribe to the ReadingChanged event
            _orientationSensor.ReadingChanged += OrientationSensor_ReadingChanged;
        }
        else
        {
            _sb.AppendLine("Orientation sensor not available.");
            StatusTextBlock.Text = _sb.ToString();
        }
    }

    private async void OrientationSensor_ReadingChanged(OrientationSensor sender, OrientationSensorReadingChangedEventArgs args)
    {
        // Update UI on the UI thread
        await Dispatcher.RunAsync(CoreDispatcherPriority.High, () =>
        {
            var reading = args.Reading;
            _sb.Clear();
            _sb.AppendLine($"Timestamp: {reading.Timestamp}");

            if (reading.Quaternion != null)
            {
                _sb.AppendLine($"Quaternion: X={reading.Quaternion.X:F3}, Y={reading.Quaternion.Y:F3}, Z={reading.Quaternion.Z:F3}, W={reading.Quaternion.W:F3}");
            }

            if (reading.RotationMatrix != null)
            {
                _sb.AppendLine($"Rotation Matrix: ");
                _sb.AppendLine($"  M11={reading.RotationMatrix.M11:F3}, M12={reading.RotationMatrix.M12:F3}, M13={reading.RotationMatrix.M13:F3}");
                _sb.AppendLine($"  M21={reading.RotationMatrix.M21:F3}, M22={reading.RotationMatrix.M22:F3}, M23={reading.RotationMatrix.M23:F3}");
                _sb.AppendLine($"  M31={reading.RotationMatrix.M31:F3}, M32={reading.RotationMatrix.M32:F3}, M33={reading.RotationMatrix.M33:F3}");
            }

            if (reading.YawPitchRollAccuracy != MagnetometerAccuracy.Unknown)
            {
                 _sb.AppendLine($"Accuracy: {reading.YawPitchRollAccuracy}");
            }

            StatusTextBlock.Text = _sb.ToString();
        });
    }

    // Remember to unsubscribe when the page is no longer needed
    protected override void OnNavigatedFrom(NavigationEventArgs e)
    {
        if (_orientationSensor != null)
        {
            _orientationSensor.ReadingChanged -= OrientationSensor_ReadingChanged;
        }
        base.OnNavigatedFrom(e);
    }
}
                

See Also

• Sensors Overview
• Simple Orientation Sensor