in my case I don't want any data transfer
Some data must go between the phone and the watch. I guess you mean that you don't want to fiddle with Bluetooth protocols and so forth, well don't worry, it's all wrapped up in an easy SDK. You send the data via a normal Android intent (example below). The Sony app does the complicated bit.
In actual fact all of a SmartWatch control's code runs on the phone. The watch is practically just a remote screen with input and vibrate. So you can easily have an Android app, with a button that calls this:
import com.sonyericsson.extras.liveware.aef.control.Control;
/**
* Start repeating vibrator
*
* @param onDuration
* On duration in milliseconds.
* @param offDuration
* Off duration in milliseconds.
* @param repeats
* The number of repeats of the on/off pattern. Use
* {@link Control.Intents#REPEAT_UNTIL_STOP_INTENT} to repeat
* until explicitly stopped.
*/
protected void startVibrator(int onDuration, int offDuration, int repeats) {
Intent intent = new Intent(Control.Intents.CONTROL_VIBRATE_INTENT);
intent.putExtra(Control.Intents.EXTRA_ON_DURATION, onDuration);
intent.putExtra(Control.Intents.EXTRA_OFF_DURATION, offDuration);
intent.putExtra(Control.Intents.EXTRA_REPEATS, repeats);
sendToHostApp(intent);
}
There are various precursor steps required for all SmartWatch apps, so I recommend you go through the normal hello world apps first, it's the quickest way to get to what you want. http://developer.sonymobile.com/2013/09/25/how-to-create-an-app-extension-for-sony-smartwatch-2/