PC-based automation of a multi-mode control for an irrigation system

This paper describes the design and implementation of a low-cost multi-mode control for an irrigation system built around a personal computer (PC). The system uses in-situ soil water potential measurements, the weather condition parameters and the set points data provided by the user to decide when and how much water to apply to the irrigated field. The soil moisture content and the climatic parameters are monitored by a microprocessor-based data acquisition and distribution controller system under the supervision of the host computer. A bi-directional serial link allows the host computer to receive, store and display in real-time the overall irrigation system status on the PC's screen. Also, the PC has the capability to transmit data to the controller and instruct it to operate in one of the three possible modes. The firmware code written in assembly language and stored in an EEPROM along with a Delphi-based friendly graphical user interface was developed to manage irrigation and other related practices such as fertigation. Full circuit and program codes were implemented to verify system operation.