| The hardware layout and software development for single chip microprocessor automatic micro-irrigation controller and system programming are presented in detail in this paper. Based on the AT89C51 single chip microprocessor, the whole system consists of soil moisture sensors, signal transfer circuit, keyboard and monitor display circuit, out port control circuit, malfunction alarm circuit as well as system software. This controller can control multi-input and multi-output. It can work in several ways such as closed loop control with sensors, opened loop control based on the preset timing program. In addition, it has automatic alarm function when the soil moisture exceeds the preset range.As far as the hardware design is concerned, here chose the HM1500 capacitive moisture sensor as the soil moisture sensor, ADC0809 as the A/D conversion, independent key as the keyboard, LED display unit as the monitor display and chose the simple piezoelectric buzzer as the malfunction alarm device. The out port control circuit is composed of AT89C51, triode, photoelectric coupler, relay, electromagnetic valve and so on. The software designing adopt the popular modularized structure. The development of software programs apply C51 language entirely. The primary programs are main program, keyboard scanning subroutine, A/D sampling subroutine, timer presettingsubroutine. Meanwhile, the efficient anti-interference measures are adopted during the design of the hardware and software.The successive debug experiments prove that this controller is characterized by high reliability, capable control function. The system has a bright prospect for development and application. In addition, suggestions about further development and improvement of the irrigation controller are made in this paper.
|
PDF Full Text Request