title: Implementation of TYPE_SIGNIFICANT_MOTION sensor in android
body: <p>In 4.4, Google introduced the <a href="http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_SIGNIFICANT_MOTION" rel="nofollow">Significant Motion Sensor</a>. </p>
  
  <p>Assuming that it is software implemented, using hardware sensors like the accelerometer and gyroscope, I'd like to know how exactly it was done (I couldn't find it in the sources as well).</p>