Exchange of information between Activity and Service (vice versa)

I am studying services on android and I have a little problem, I try to see how the exchange of information works both from the activy to the service and vice versa, I have no problems passing data from the activity to the service, but I got this form that is through a broadcast that does not execute the passage of data at the time I want.

This is my main class

package com.example.jesus.servicio;

// here are all the respective imports

public class MainActivity extends AppCompatActivity {

    Button btn ;

    public String algo = "Conteo Regresivo, Ejecutado en el Servicio";

 MyReceiver Recepcion;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btn = findViewById(R.id.button);

        Recepcion = new MyReceiver();
        IntentFilter obtener = new IntentFilter();
        obtener.addAction(servicio.MY_ACTION);
        registerReceiver(Recepcion, obtener);

//Boton que ejecuta el servicio

        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
//forma 1 de llamar a un servicio
//              startService(new Intent(getApplicationContext(),servicio.class));
//forma 2  de llamr a un servicio pero pasando datos
                Intent servicio = new Intent(MainActivity.this, servicio.class);
                servicio.putExtra("datos",algo);
                startService(servicio);
            }
        });
    }

// Metodo de Receptor
    private class MyReceiver extends BroadcastReceiver {

        @Override
        public void onReceive(Context hola , Intent valor) {
            // TODO Auto-generated method stub

            int datapassed = valor.getIntExtra("DATAPASSED", 0);

            Toast.makeText(MainActivity.this, "Los numeros vienen del Servicio!\n"
                            + "Numero: " + String.valueOf(datapassed)+ " fue pasado, del servicio",
                    Toast.LENGTH_LONG).show();

        }

    }
}

and here is my service

package com.example.jesus.servicio;

import android.app.Notification;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.support.v4.app.NotificationCompat;
import android.util.Log;
import android.widget.Toast;



public class servicio extends Service {

    final static String MY_ACTION = "La accion a ejecutar";

    public static String TAG = "El servicio";

    public servicio() {
    }

    @Override
    public void onCreate() {
        super.onCreate();
        Log.d(TAG, "Inicio");

    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {

        Intent enviar= new Intent();
        enviar.setAction(MY_ACTION);
        enviar.putExtra("DATAPASSED", 365);
        sendBroadcast(enviar);

        Log.d(TAG, "el body del servicio");
// Como obtener el dato de la forma 2 puede ser en Star command o en el Create o en el mismo Destroy.
        String datosObtenidos = intent.getStringExtra("datos");
        Toast.makeText(this, datosObtenidos, Toast.LENGTH_SHORT).show();
            int i;
            for(i=2; i>=0; i--){
                Log.d(TAG, "Cuenta: "+i);
                Toast.makeText(this, ""+ i, Toast.LENGTH_SHORT).show();
            }



        stopSelf();

//Esto funciona para retornar algo q se desee de este servicio
       return super.onStartCommand(intent, flags, startId);
    }


    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        throw new UnsupportedOperationException("Not yet implemented");
    }



}

Note that in my service I try to perform the method of sending the data, before the method that receives data and executes a simple counting code.

What am I doing wrong? I want the shipping method to run first and send the data to the activity and then the service receives the activity data and performs the process indicated there ..