MainActivity_FirebaseLed.java

package haydut.firebaseled;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
public class MainActivity extends AppCompatActivity {
    int i = 2;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button BTNLed = (Button)findViewById(R.id.button3);
        //Firebase bağlantısını yapıyoruz
        FirebaseDatabase database = FirebaseDatabase.getInstance();
        //LedStatus alanına işlem yapacağız
        final DatabaseReference myRef = database.getReference("LEDStatus");
        BTNLed.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(i%2==0){
                    //i çift ise 1 yaz
                    myRef.setValue(1);
                }else{
                    //i tek ise 0 yaz
                    myRef.setValue(0);
                }
                i++;
            }
        });
    }
}