RANCANG BANGUN SISTEM AKUISISI DATA SUHU DAN KELEMBABAN UDARA MENGGUNAKAN KOMPUTER

Abstract

Data acquisition system of temperature and humidity used a computer has been designed and realization. The system can be applied for various purposes such as on early warning systems, weather forecasting or controlling a process. The system also can be used to monitor temperature and humidity on the storage of food so that the quality of food is guaranteed and in the greenhouse in order to the growth of plants can be observed. The data acquisition system of temperature and humidity consist of ATmega8535 microcontroller as a serial data transmission device to a computer. As the humidity sensor is used HSM-20G and LM35 for the temperature sensor. Both of output the sensor associated with buffer circuit first before being put into internal ADC ATmega8535 microcontroller on pin ADC0 and ADC1. The measured data from both sensors will be sent to the computer used RS-232 protocol serially. From this research was obtained that the Borland Delphi 7 can displayed the measured data from humidity sensor HSM-20G and temperature sensor LM35 in graphical form of humidity and temperature versus time and able to save the data in monitoring tables that contained in Microsoft Access too. From the tests, it has been done with humidity gauge standard HTC-608 and thermometer gauge standard SANWA CD 772 was obtained linear correlation coefficient of r = 99,7%.