基于单片机的温度控制系统设计毕业论文

I摘要温度是表征物体冷热程度的物理量，是工农业生产过程中一个很重要而普遍的参数。由于温度测量的普遍性，温度传感器的数量在各种传感器中居首位。温度控制的发展引入单片机后，可以降低对某些硬件电路的要求。基于单片机的温度控制系统，可以实现对温度的精确控制。本文以温室为研究对象，以AT89C51单片机为核心所实现的温度控制系统具有自动完成数据采集、数据处理、数据转换控制、键盘终端处理及显示的功能。当实际温度低于设定值，PTC进行加热，反之PTC就停止加热。实际温度超上限或者低下限时，系统自动报警。温度控制采用的是双位控制，简单易行，在精度要求不是特别高的温室，可行度很高。最后对系统进行调试并在PROTEUS里仿真，结果表明该系统原理可行。又在一个小空间进行试验，误差在1℃左右，结果符合预期。运行稳定、控制效果好、性价比高。关键词：单片机，温度控制，DS18B20，温室AbstractTemperatureisthephysicalquantitycharacterizingthetemperatureextentofobjects;itisanimportantandgeneralparameterinindustrialandagriculturalproductionprocess.Duetotheuniversalityoftemperaturemeasurement,thequantityoftemperaturesensoroccupiesfirstplaceamongvarioussensors.Itcanlowertherequirementsofsomecircuitsafterintroducingthedevelopmentoftemperaturecontrolintomicrocontrollerunit.Itcanalsoachieveprecisecontrolofthetemperature,basedonthetemperaturecontrolsystemofmicrocontrollerunit.Inthisarticle,greenhouseistheobjectofstudy.ThetemperaturecontrolsystemwhichtakesAT89C51asthecorehasthefunctionofautomaticcompletedataacquisition,dataprocessing,dataconversioncontrol,keyboardterminalprocessinganddisplay.Whentheactualtemperatureisbelowthesetvalue,PTCstartsheating,onthecontrary,itstopsheating.Whentheactualtemperatureexceedstheupperorlowerlimit,thesystemgivesanalarmautomatically.Temperaturecontrolissimpleandeasywithadualpositioncontrol.Itishighlyfeasibleinthegreenhousewheretheaccuracyrequirementsarelessstrict.TheresultsshowstheprincipleisavailableafterdebuggingthesystemandsimulatinginProteus,wealsoconductedthesametrialinasmallerroom,andtheerrorisabout1℃,whichisinlinewithexpectations.Thesystemisstable,easytocontrolandcost-effective.Keyword:microcontrollerunit,temperaturecontrol,DS18B20,greenhouse中国农业大学学士论文目录II目录摘要..................................................................IAbstract...............................................................I目录................................................................II第一章绪论............................................................11.1课题研究背景及意义..............................................11.2国内外研究现状..................................................11.2.1国外研究现状...............................................11.2.2国内研究现状...............................................11.2.3总的发展阶段...............................................21.3课题研究的内容..................................................2第二章硬件系统总体方案设计............................................32.1硬件系统总体设计方案一..........................................32.2硬件系统总体设计方案二..........................................42.3硬件系统的方案选择..............................................4第三章控制系统硬件设计................................................63.1单片机..........................................................63.2数字温度计DS18B20..............................................93.2.1DS18S20数字温度计的主要特性...............................93.34X4键盘........................................................93.4数码管.........................................................103.5光电耦合器.....................................................123.6双向晶闸管.....................................................133.7PTC加热器.....................................................143.8反相器7406....................................................153.9双四输入与门74LS21.............................................163.9蜂鸣器.........................................................16中国农业大学学士论文目录III第四章控制系统软件设计...............................................174.1主程序模块设计.................................................174.1.1主程序流程图..............................................174.2温度采集模块程序设计...........................................184.2.1DS18B20的时序............................................184.2.3读温度子程序流程图.......................................204.3温度设定模块程序设计...........................................214.3.1中断服务子程序............................................214.3.2键盘扫描子程序...........................................214.4温度显示模块设计...............................................234.4.1设定值显示子程序..........................................234.4.2实际值显示子程序.........................................244.5温度控制模块设计...............................................254.5.1双位控制算法设计..........................................254.5.2温度控制子程序流程图......................................254.6报警模块程序设计...............................................26第五章结果分析.......................................................275.1PROTEUS仿真...................................................275.1.1键盘设定温度仿真.........................................275.1.2温度采集仿真.............................................285.1.3整体仿真.................................................285.2实际运行结果...................................................29第六章总结与展望.....................................................316.1总结...........................................................316.2展望...........................................................31致谢.................................................................32附录程序..............................................................33参考文献........................