I m looking for the best practice to implement a service for logging gps- or other sensor-values periodically (every 10-60 sec). The service should deal with the standby mode, when the phone goes asleep.
Any help, even pseudo-code, is very much appreciated!
It looks like it is impossible to let the orientation sensors work constantly for hours even though the device may fall asleep (refer to http://code.google.com/p/android/issues/detail?id=3708#makechanges
As soon as the display goes off, the sensors will do alike... :(
I now implemented a wakelock (needs permission)
<uses-permission android:name="android.permission.WAKE_LOCK" />
in conjunction with a timer and a broadcastreciever that will turn the display back on again. This is of course crazy for battery life but I found no other way so far.
This is my onCreate method in the service:
@Override
public void onCreate() {
mNM = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
CONTEXT = this;
PowerManager pm = (PowerManager) CONTEXT.getSystemService(Context.POWER_SERVICE);
this.mWakeLock = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP, "my tag");
mWakeLock.acquire();
Log.d(TAG, "Wakelock acquired");
// register receiver that handles screen on and screen off logic
IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
BroadcastReceiver mReceiver = new ScreenReceiver();
registerReceiver(mReceiver, filter);
}
this the onStart method of the service:
@Override
public void onStart(Intent intent, int startid) {
Toast.makeText(this, "My Service Started", Toast.LENGTH_SHORT).show();
Log.d(TAG, "onStart");
boolean screenOn = intent.getBooleanExtra("screen_state", false);
if (!screenOn) {
Log.d(TAG, "Screen is on");
} else {
Log.d(TAG, "Screen is off");
Timer timer = new Timer("DigitalClock");
timer.schedule(new TimerTask() {
@Override
public void run() {
Log.d(TAG,"Waiting 1 sec for switching the screen back on again...");
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
mWakeLock = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP,
"my tag");
mWakeLock.acquire();
}
}, 1000);
mWakeLock.acquire();
}
}
and this is the BroadcastReceiver class:
public class ScreenReceiver extends BroadcastReceiver { private boolean screenOff; @Override public void onReceive(Context context, Intent intent) { if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) { screenOff = true; } else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) { screenOff = false; } Intent i = new Intent(context, MyService.class); i.putExtra("screen_state", screenOff); context.startService(i); }
}
This workaround will also do with a device UN-plugged from the debugger via USB (I first had an issue with this).
Please let me know if you have a better solution, or if there is fix in 2.3. Thanx!