I posted this same question on StackOverflow if anyone wants the karma for answering it there.
This is on an Android phone running 2.3.3 Gingerbread. I am trying to log a GPS location while the screen is off. When the screen is on, the GPS gives correct outputs... driving around in my car I have a phone hooked up to my laptop and I read the output with logcat. Under the same conditions, when I turn off the screen the GPS gives the same location over and over, until I turn on my screen again at which time it works properly. Here is my manifest file (note the WAKE_LOCK and GPS permissions as well as the LocationService definition): <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"; package="com.joshuajwitter.backgroundgpstest" android:versionCode="1" android:versionName="1.0" > <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> <uses-permission android:name="android.permission.WAKE_LOCK" /> <uses-sdk android:minSdkVersion="10" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <activity android:name=".BackgroundGPSTestActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <service android:name=".service.LocationService" > <intent-filter> <action android:name="com.joshuajwitter.backgroundgpstest.service.LocationService" / > </intent-filter> </service> </application> </manifest> Here is my background service: package com.joshuajwitter.backgroundgpstest.service; import android.app.Service; import android.content.Context; import android.content.Intent; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Bundle; import android.os.IBinder; import android.os.PowerManager; import android.os.PowerManager.WakeLock; import android.util.Log; public class LocationService extends Service { private static final String TAG = "LocationService"; // the location manager and listener LocationManager m_locationManager; GPSLocationListener m_gpsLocationListener; // the dreaded wakelock WakeLock m_wakeLock; @Override public IBinder onBind(Intent intent) { return null; } @Override public void onStart(Intent intent, int startId) { Log.d(TAG, "Starting the LocationService"); // acquire the wakelock Log.d(TAG, "Acquiring the wake lock"); m_wakeLock.acquire(); } @Override public void onCreate() { // get the wakelock PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE); m_wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "String Wake Lock"); // instantiate the gps listener m_gpsLocationListener = new GPSLocationListener(); // get the location manager m_locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); // request location updates every 5 seconds m_locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5000, 0, m_gpsLocationListener); } @Override public void onDestroy() { Log.d(TAG, "Stopping the LocationService"); // if the wakelock is held if (m_wakeLock.isHeld()) { // release it Log.d(TAG, "Releasing the wake lock"); m_wakeLock.release(); } // remove the listener m_locationManager.removeUpdates(m_gpsLocationListener); } private class GPSLocationListener implements LocationListener { @Override public void onLocationChanged(Location location) { Log.d(TAG, "Got a new location frome the LocationManager [" + location.getLatitude() + ", " + location.getLongitude() + "]"); } @Override public void onProviderDisabled(String provider) { } @Override public void onProviderEnabled(String provider) { } @Override public void onStatusChanged(String provider, int status, Bundle extras) { } } } ..and here is the activity that starts and stops the service: package com.joshuajwitter.backgroundgpstest; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import com.joshuajwitter.backgroundgpstest.service.LocationService; public class BackgroundGPSTestActivity extends Activity { private boolean m_serviceRunning = false; private Button m_mainButton; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // get the main button m_mainButton = ((Button) findViewById(R.id.mainButton)); // set the main button listener m_mainButton .setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { // if the service is not running if (!m_serviceRunning) { // start the service startService(); } else { // start the service stopService(); } } }); } private void startService() { m_serviceRunning = true; startService(new Intent(this, LocationService.class)); m_mainButton.setText("Stop Background GPS Service"); } private void stopService() { m_serviceRunning = false; stopService(new Intent(this, LocationService.class)); m_mainButton.setText("Start Background GPS Service"); } } When I run the service and keep the screen on, I get the correct GPS latitude and longitude for my position. When I turn the screen off, however, I get the same repeating output: 01-31 15:48:58.467: D/LocationService(11752): Got a new location frome the LocationManager [-36.879621, -7.734375] 01-31 15:48:59.467: D/LocationService(11752): Got a new location frome the LocationManager [-36.879621, -7.734375] 01-31 15:49:00.467: D/LocationService(11752): Got a new location frome the LocationManager [-36.879621, -7.734375] 01-31 15:49:01.467: D/LocationService(11752): Got a new location frome the LocationManager [-36.879621, -7.734375] 01-31 15:49:02.477: D/LocationService(11752): Got a new location frome the LocationManager [-36.879621, -7.734375] 01-31 15:49:03.477: D/LocationService(11752): Got a new location frome the LocationManager [-36.879621, -7.734375] 01-31 15:49:04.467: D/LocationService(11752): Got a new location frome the LocationManager [-36.879621, -7.734375] When I turn the screen back on, I get correct GPS values once more. Here's the kicker: Google Maps Navigation runs on my phone with the screen off. If I run it at the same time as my test program, the same behavior occurs... the Navigation app gets notified of the correct coordinates while my test app repeats the same lat/long over and over. Thanks for any input! -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
