In the system, Kosong.java used to receiving data from PHP that has delay every three seconds. It will be shown in TextView on android window. MainActivity.java is the main class for controlling microcontroller. It send data from toggle button into database. Then it will get the string if the data get to database. If it doesn’t get string, it will not receive any string because it is not connected to database that will send an echo into android. On MainMenu.java it is used to choose which window, whether it is monitoring or controlling. For MyTimerTask.java it is used to run the timer to control for updating data that received from PHP.