title: How to read current sensor values in Tizen native app for wearable (Galaxy Active 2)
body: <p>I've built a simple watchface for a Samsung Galaxy Active 2 using Tizen Studio, native app.
  I have added some of the "health" info to the face: pedometer and heartrate monitor.</p>
  
  <p>Q: I know how to setup a listener and callback so that I can get notified when the heartrate (or step count) <strong>changes</strong>, but I cannot find how to just read the current / last read HRM value. I know this must be possible since other watchfaces do this ... just don't know how.</p>
  
  <p>Code for the listener/callback method:</p>
  
  <pre><code>    sensor_get_default_sensor(SENSOR_HRM, &amp;sensor);
      ret = sensor_create_listener(sensor, &amp;hrmSensorListener);
      if( ret != SENSOR_ERROR_NONE)
          dlog_print(DLOG_ERROR, LOG_TAG, "failed to get hrm sensor. err = %d", ret);
  
      ret = sensor_listener_set_event_cb(hrmSensorListener, 20000, hrm_sensor_callback, face);
      if( ret != SENSOR_ERROR_NONE)
          dlog_print(DLOG_ERROR, LOG_TAG, "failed to set hrm sensor listener. err = %d", ret);
  
      sensor_listener_set_option(hrmSensorListener, SENSOR_OPTION_DEFAULT);
      sensor_listener_start(hrmSensorListener);
  </code></pre>
  
  <p>This means that when the watchface starts, there is a period when the HRM or step count is not updated, and this is a bit annoying.</p>
  
  <p>How do I read the <strong>current</strong> value of the sensor?</p>