title: PowerManager wakelock not waking device up from service
body: <p>I've an app that has a background service running every minute. I want the service to wake the device up if it's asleep. I am using a PowerManager but the device doesn't wake up. Any ideas why? Thanks in advance.</p>
  
  <pre><code>@Override
  protected void onHandleIntent(Intent intent) {
      PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
      PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK,
              "My Tag");
      wl.acquire();
      // do work as device is awake
      wl.release();
  }
  </code></pre>
  
  <p>[edit1]</p>
  
  <p>This is how i start the service from an Activity.</p>
  
  <pre><code>// get a Calendar object with current time
  Calendar cal = Calendar.getInstance();
  // add 5 minutes to the calendar object
  cal.add(Calendar.MINUTE, 1);
  Intent intent = new Intent(getApplicationContext(), AlarmReceiver.class);
  intent.putExtra("alarm_message", "sending outstanding transactions");
  // In reality, you would want to have a static variable for the
  // request code instead of 192837
  PendingIntent sender = PendingIntent.getBroadcast(
          getApplicationContext(), 192837, intent,
          PendingIntent.FLAG_UPDATE_CURRENT);
  // Get the AlarmManager service
  AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
  // am.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(), sender);
  // 86400000 = 24 hours
  // 43200000 = 12 hours
  // 3600000 = 1hr
  // 1800000 = 30 mins
  // 300000 = 5 mins
  am.setRepeating(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(),60000,sender);
  </code></pre>
  
  <p>AlarmReceiver class</p>
  
  <pre><code>import android.content.BroadcastReceiver;
  import android.content.Context;
  import android.content.Intent;
  import android.widget.Toast;
  import android.os.Bundle;
  
  public class AlarmReceiver extends BroadcastReceiver {
  
      @Override
      public void onReceive(Context context, Intent intent) {
          try {
  
              Bundle bundle = intent.getExtras();
              String message = bundle.getString("alarm_message");
              // Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
              Intent myIntent = new Intent(context,
                      SendOutstandingTransactions.class);
              myIntent.setAction("com.carefreegroup.startatboot.MyService");
              context.startService(myIntent);
          } catch (Exception e) {
              Toast.makeText(
                      context,
                      "There was an error somewhere, but we still received an alarm",
                      Toast.LENGTH_SHORT).show();
              e.printStackTrace();
          }
      }
  }
  </code></pre>
  
  <p>The following class calls the Activity which I want to start when the device is asleep.</p>
  
  <p>SendOutstandingTransactions IntentService.</p>
  
  <pre><code>protected void onHandleIntent(Intent intent) {
      PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
      PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK,
              "My Tag");
      wl.acquire();
      if (hasMessageDisplayed == false) {
          Intent i = new Intent(this, DisplayMessageActivity.class);
          i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
          startActivity(i);
      }
      wl.release();
  }
  </code></pre>
  
  <p>[edit2]</p>
  
  <pre><code>@Override
  public void onDestroy() {
      super.onDestroy();
      PowerManager pm = (PowerManager) this.getSystemService(Context.POWER_SERVICE);
      PowerManager.WakeLock wl = pm.newWakeLock(
              PowerManager.PARTIAL_WAKE_LOCK, "com.something.alarm");
      // Acquire the lock
      if (wl.isHeld()) wl.release();
  }
  </code></pre>