I陕西理工学院毕业设计基于单片机的TDS水质测试仪设计王春(陕理工物理与电信工程学院电子信息工程专业1103班,陕西汉中,723000)指导老师:秦伟[摘要]本设计通过研究分析TDS(溶解性总固体)测量的原理,设计了一款以STC89C52单片机为核心的水质测试仪。本设计通过电导率测量电路实现电导率信号的采集,并采用温度传感器进行温度测量,使用温度补偿方法减小温度对电导率测量值的影响,通过单片机程序进行相关计算得出TDS值。该设计包括信号采集电路、按键电路、温度测量电路、数码管显示电路。该水质测试仪结构简单,操作容易,低成本,测量的TDS值对帮助人们了解水质情况起到了非常重要的作用。[关键字]STC89C52,溶解性总固体,水质测试II陕西理工学院毕业设计II陕西理工学院毕业设计ThedesignofTDSwaterqualitytesterbasedonSCMWangChun(Grade03,Class11,MajorElectronicInformationEngineering,Collegeofphysicsandtelecommunicationengineering,ShaanxiUniversityofTechnology,Hanzhong723000,Shaanxi)Tutor:QinWei[Abstract]ThisdesignstudiestheprincipleofTotalDissolvedSolids(TDS)measurement.AnditdesignsawaterqualitytesterwhichtakesSTC89C52SingleChipMicrocomputer(SCM)asthecore.Thedesigncollectstheelectricalconductivitysignalbyelectricalconductivitymeasurementcircuit.Anditusestemperaturesensortomeasuretemperature.Anditreducestheinfluenceoftemperatureontheelectricconductivitymeasurementbyusingthetemperaturecompensationmethod.AndthroughtheSCMprogramforcorrelationcalculationtocalculatethevalueofTDS.Thedesignincludessignalacquisitioncircuit,keycircuit,temperaturemeasurementcircuitanddigitaltubedisplaycircuit.Thewaterqualitytestinginstrumenthastheadvantagesofsimplestructure,easyoperation,lowcost,whichplayaveryimportantroleinhelpingpeopletounderstandthesituationofwaterquality.[keywords]STC89C52,TDS,waterqualitytesting陕西理工学院毕业设计目录引言.......................................................11设计内容与方案............................................21.1设计内容与要求...........................................21.2方案论证.................................................21.3方案选择.................................................21.3.1单片机的选择........................................31.3.2温度传感器的选择....................................32系统硬件电路设计..........................................42.1单片机最小系统...........................................42.1.1单片机STC89C52简介.................................42.1.2单片机最小系统......................................42.2TDS值测量电路...........................................52.2.1TDS值测量原理......................................52.2.2TDS测量电路........................................62.3温度补偿原理与电路.......................................82.3.1温度补偿原理........................................82.3.2温度测量电路........................................82.4数码管显示电路...........................................92.4.1共阳极数码管工作原理................................92.4.2数码管显示电路.....................................102.5按键电路................................................102.6总体电路图..............................................113系统软件设计.............................................123.1软件设计的整体思想......................................123.2总流程图与各部分流程图..................................123.2.1总流程图...........................................123.2.2电导率测量........................................133.2.3温度测量流程图................