PC Based Data Acquisition System for Humidity and Moisture

摘要

DAQ (Data Acquisition) is simply the process of bringing a real time data such as a voltage into the computer for processing and manipulating the data. It is a Physical phenomenon, which represents the real time data that we are trying to measure. For the purpose of processing and transmitting the data, analog to digital converter is used. A data acquisition system that performs conversion of analog signal to digital data and the digital data to analog signal is interfaced to a pc to measure the data from the physical variables. In this paper we have used the humidity and soil moisture sensors to acquire the data from the environment. We have developed signal conditioning circuits to obtain significant voltages form both sensors. We then transformed the analog voltage into digital signal by using ADC 0809 and the processing part is done by using ATMEL89C52 microcontroller. Keil software has beenused in this paper. Transmitter out (7th pin) of MAX232 is connected to USB port of PC to monitor the values on the screen.