智能灌溉系统的设计论文

TianjinUniversityofTechnologyandEducation毕业设计二○一一年六月智能灌溉系统的设计DesignofIntelligentIrrigationSystem2011年6月摘要近几年来，随着全球水资源的日趋紧张，世界各国都在积极探索行之有效的节水途径和措施。自动控制节水灌溉技术的高低代表着农业现代化的发展状况，灌溉系统自动化水平较低是制约我国高效农业发展的主要原因，节水灌溉作为一项现代化的工II程技术，无论是工程节水、农业节水，还是管理节水都必须建立在节水灌溉设备实现产业化生产的基础上。节水灌溉技术是为了解决水资源不足，提高灌溉效率而发展起来的现代灌溉技术之一。本课题设计了一个智能灌溉系统，该系统以AT89S52单片机为控制核心，采用模块化的设计方案，由温湿度采集模块、时钟模块、步进电机控制模块、键盘接口模块和液晶显示模块组成。温湿度采集模块以DHT11温湿度传感器为核心，时钟模块主要由DS1302和32.768kHz的晶体组成，步进电机控制电路模块采用了达林顿驱动芯片ULN2003，显示电路模块主要由LCD12864构成。在闭环（自动）模式下，该系统能自动对土壤的温湿度进行检测，当实际湿度低于警戒值时单片机自动启动步进电机进行灌溉。关键词：AT89S52；DHT11温湿度传感器；ULN2003达林顿驱动；LCD12864；DS1302ABSTRACTInrecentyears,alongwiththeglobalwaterresourcesisnervous,countriesintheworldexploreactivelyeffectivewaysandmeasuresofwater-saving.Automaticcontrolthediscretionofwater-savingirrigationtechnologiesrepresentstheagriculturalIImodernization,lowlevelofthedevelopmentsituationofirrigationsystemautomationbecomethemaincauseofrestrictinghigh-efficientagriculturedevelopment,water-savingirrigationisamodernengineeringtechnology,whetherengineeringsectionwater,watersaving,ormanagementofagriculturalwatermustbebasedonthebasisofwater-savingirrigationequipmentrealizingindustrializationproduction.Water-savingirrigationtechniqueisusedtodealwiththewatershortage,improveirrigationefficiencyandbedevelopedintooneofthemodernirrigationtechniques.Thistopicdesignanintelligentirrigationsystem,thissystemselecttheAT89S52SCMascontrolcore,adoptthemodularizingdesignscheme,whichcontainthetemperatureandhumidityacquisitionmodule,PHvaluedetectionmodule,clockmodule,steppingmotorcontrolmodule,keyboardinterfacemoduleandLCDmodule.DHT11andhumiditysensorisselectedasthecoreoftemperatureandhumidityacquisitionmodule,clockmoduleismainlycomposedoftheclockDS1302andcrystalof32.768kHz,steppingmotorcontrolcircuitmoduleadoptedreachlintondrivechipULN2003,displaycircuitmoduleismainlyconsistedoftheLCD12864constitutes.Intheloop(automatically)mode,thesystemcanautomaticallydetectonsoiltemperatureandhumidity,whenactualhumidityunderalertvaluesingle-chipmicrocomputerautomaticstartsteppingmotorforirrigation.KeyWords：AT89S52;DHT11temperatureandhumiditysensor;ULN2003DarlingtonDriver;LCD12864;DS1302目录1绪论.......................................................................................................................11.1引言............................................................................................................11.2课题来源....................................................................................................11.3国内外现状................................................................................................22方案设计与论证...................................................................................................42.1总体方案论证............................................................................................42.2键盘电路....................................................................................................52.3温湿度传感器的选取.................................................................................62.3.1湿度传感器原理..............................................................................62.3.2数字温湿度传感器DHT11.............................................................73系统硬件电路设计.............................................................................................93.1AT89S52单片机的硬件结构..................................................................93.1.1单片机的结构及信号引脚..............................................................93.1.2AT89S52最小系统.....................................................................123.2直流稳压电源的设计..............................................................................133.3湿度采集模块..........................................................................................143.3.1温湿度传感器的原理...................................................................143.4pH值检测装置.........................................................................................173.5时钟模块...................................................................................................193.5.1时钟模块接线图............................................................................193.5.2DS1302内部寄存器.....................................................................213.6液晶显示模块...........................................................................................223.6.1液晶显示模块概述........................................................................223.6.2模块主要硬件构成说明................................................................233.7步进电机驱动模块...................................................................................253.7.1步进电机简介和原理....................................................................253.7.2ULN2003驱动芯片.......................................................................253.7.3步进电机驱动模块........................................................................264系统软件设计...................................................................................................274.1程序设计...................................................