A PC-Based Low Cost Multi-channel Measuring and Monitoring System

The paper involved the design and implementation of a flexible low cost PC based multichannel measuring and monitoring system by using a personal computer and a simple hardware. Weather variables such as (temperature, relative humidity, rainfall, wind speed and direction) were measured and monitored as an application to this system. The PC sound card was used as a data acquisition circuit to enter the signals to the PC, a multiplexer was used to achieve multichannel entering to the sound card, and a parallel port was used to control signals entering. Graphical User Interface (GUI) screen with virtual instruments were used to display data, time, date and analog signals in real time The results obtained from the system were compared with the results of that recorded at the meteorology office, it is found that the average error in measuring the wind speed was (7%), (3%) for wind direction, (3%) for temperature, (2%) for humidity, and (8.2%) for rainfall.