III. HARDWARE SYSTEM
The hardware system is divided into 3 part. There are microcontroller arduino, a sensor, and IEEE wireless 802. llg. The microcontroller arduino used for monitoring and controlling the green house. It is used to read the measurement value of sensor, write an input to control the stepper motor and LED module, analog-digital converter and serial communication for the flow of value from sensor. First, microcontroller get the analog voltage signal from the sensor and convert it to digital signal. After microcontroller receive the digital signal, microcontroller send the value from sensor to the Android via computer through serial communication and wireless connection.