Use the gyrometer
Learn how to use the gyrometer to detect changes in user movement.
Important APIs
Prerequisites
You should be familiar with Extensible Application Markup Language (XAML), Microsoft Visual C#, and events.
The device or emulator that you're using must support a gyrometer.
Create a simple gyrometer app
Gyrometers compliment accelerometers as game controllers. The accelerometer can measure linear motion while the gyrometer measures angular velocity or rotational motion.
Note
For a more complete implementation, see the gyrometer sample.
Instructions
Create a new project, choosing a Blank App (Universal Windows) from the Visual C# project templates.
Open your project's MainPage.xaml.cs file and replace the existing code with the following.
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
using Windows.UI.Core; // Required to access the core dispatcher object
using Windows.Devices.Sensors; // Required to access the sensor platform and the gyrometer
namespace App1
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page
{
private Gyrometer _gyrometer; // Our app' s gyrometer object
// This event handler writes the current gyrometer reading to
// the three textblocks on the app' s main page.
private async void ReadingChanged(object sender, GyrometerReadingChangedEventArgs e)
{
await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
GyrometerReading reading = e.Reading;
txtXAxis.Text = String.Format("{0,5:0.00}", reading.AngularVelocityX);
txtYAxis.Text = String.Format("{0,5:0.00}", reading.AngularVelocityY);
txtZAxis.Text = String.Format("{0,5:0.00}", reading.AngularVelocityZ);
});
}
public MainPage()
{
this.InitializeComponent();
_gyrometer = Gyrometer.GetDefault(); // Get the default gyrometer sensor object
if (_gyrometer != null)
{
// Establish the report interval for all scenarios
uint minReportInterval = _gyrometer.MinimumReportInterval;
uint reportInterval = minReportInterval > 16 ? minReportInterval : 16;
_gyrometer.ReportInterval = reportInterval;
// Assign an event handler for the gyrometer reading-changed event
_gyrometer.ReadingChanged += new TypedEventHandler<Gyrometer, GyrometerReadingChangedEventArgs>(ReadingChanged);
}
}
}
}
You'll need to rename the namespace in the previous snippet with the name you gave your project. For example, if you created a project named GyrometerCS, you'd replace namespace App1 with namespace GyrometerCS.
- Open the file MainPage.xaml and replace the original contents with the following XML.
<Page
x:Class="App1.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:App1"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">
<Grid x:Name="LayoutRoot" Background="#FF0C0C0C">
<TextBlock HorizontalAlignment="Left" Height="23" Margin="8,8,0,0" TextWrapping="Wrap" Text="X-Axis:" VerticalAlignment="Top" Width="46" Foreground="#FFFDFDFD"/>
<TextBlock x:Name="txtXAxis" HorizontalAlignment="Left" Height="23" Margin="67,8,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="88" Foreground="#FFFDFAFA"/>
<TextBlock HorizontalAlignment="Left" Height="20" Margin="8,52,0,0" TextWrapping="Wrap" Text="Y Axis:" VerticalAlignment="Top" Width="46" Foreground="White"/>
<TextBlock x:Name="txtYAxis" HorizontalAlignment="Left" Height="24" Margin="54,48,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="80" Foreground="#FFFBFBFB"/>
<TextBlock HorizontalAlignment="Left" Height="21" Margin="8,93,0,0" TextWrapping="Wrap" Text="Z Axis:" VerticalAlignment="Top" Width="46" Foreground="#FFFEFBFB"/>
<TextBlock x:Name="txtZAxis" HorizontalAlignment="Left" Height="21" Margin="54,93,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="63" Foreground="#FFF8F3F3"/>
</Grid>
</Page>
You'll need to replace the first part of the class name in the previous snippet with the namespace of your app. For example, if you created a project named GyrometerCS, you'd replace x:Class="App1.MainPage" with x:Class="GyrometerCS.MainPage". You should also replace xmlns:local="using:App1" with xmlns:local="using:GyrometerCS".
- Press F5 or select Debug > Start Debugging to build, deploy, and run the app.
Once the app is running, you can change the gyrometer values by moving the device or using the emulator tools.
- Stop the app by returning to Visual Studio and pressing Shift+F5 or select Debug > Stop Debugging to stop the app.
Explanation
The previous example demonstrates how little code you'll need to write in order to integrate gyrometer input in your app.
The app establishes a connection with the default gyrometer in the MainPage method.
_gyrometer = Gyrometer.GetDefault(); // Get the default gyrometer sensor object
The app establishes the report interval within the MainPage method. This code retrieves the minimum interval supported by the device and compares it to a requested interval of 16 milliseconds (which approximates a 60-Hz refresh rate). If the minimum supported interval is greater than the requested interval, the code sets the value to the minimum. Otherwise, it sets the value to the requested interval.
uint minReportInterval = _gyrometer.MinimumReportInterval;
uint reportInterval = minReportInterval > 16 ? minReportInterval : 16;
_gyrometer.ReportInterval = reportInterval;
The new gyrometer data is captured in the ReadingChanged method. Each time the sensor driver receives new data from the sensor, it passes the values to your app using this event handler. The app registers this event handler on the following line.
_gyrometer.ReadingChanged += new TypedEventHandler<Gyrometer,
GyrometerReadingChangedEventArgs>(ReadingChanged);
These new values are written to the TextBlocks found in the project's XAML.
<TextBlock HorizontalAlignment="Left" Height="23" Margin="8,8,0,0" TextWrapping="Wrap" Text="X-Axis:" VerticalAlignment="Top" Width="46" Foreground="#FFFDFDFD"/>
<TextBlock x:Name="txtXAxis" HorizontalAlignment="Left" Height="23" Margin="67,8,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="88" Foreground="#FFFDFAFA"/>
<TextBlock HorizontalAlignment="Left" Height="20" Margin="8,52,0,0" TextWrapping="Wrap" Text="Y Axis:" VerticalAlignment="Top" Width="46" Foreground="White"/>
<TextBlock x:Name="txtYAxis" HorizontalAlignment="Left" Height="24" Margin="54,48,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="80" Foreground="#FFFBFBFB"/>
<TextBlock HorizontalAlignment="Left" Height="21" Margin="8,93,0,0" TextWrapping="Wrap" Text="Z Axis:" VerticalAlignment="Top" Width="46" Foreground="#FFFEFBFB"/>
<TextBlock x:Name="txtZAxis" HorizontalAlignment="Left" Height="21" Margin="54,93,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="63" Foreground="#FFF8F3F3"/>