电子式里程表摘要里程表广泛应用于各类机车，传统的机械式里程表虽然稳定可靠，但功能单一、易受磨损。随着电子技术的迅猛发展，电子式里程表得以广泛应用，现在很多轿车仪表已经使用电子车速里程表，本设计介绍一种基于单片机的智能电子里程表。该电子式里程表是一种数字式仪表，主要由车速表和里程表两部分组成，其传感器采用无接触测量的光电传感器。它不仅可显示车辆行驶的总里程，也可显示一段时间的阶段里程，还可显示车速，以及实现超速报警等功能，并具有较强的再开发能力。它的实现方式是，通过安装在汽车转轴上的测量盘，用光电式转速传感器检测转速的脉冲信息，在脉冲状态下，将转速的变化转换成光通量的变化，再通过光电转换元件将光通量的变化转换成电量的变化，接着通过频率测量电路将脉冲信号输入到单片机中，然后依据电量与转速的函数关系实现转速测量，再通过计算，从而得出里程、车速的信息，并由LED显示器显示出来。并且该电子式里程表累积的里程数字存储在非易失性的EEPROM存储器内，在无电状态下数据也能保存。关键词：AT89S51单片机；里程表；光电传感器；LED显示器；存储器AbstractVehicleodometerisappliedineachkindofmotorcycleextensively,althoughthetraditionalmachinetypeodometerstableandcredible,butthefunctionofitissingleandbeeasilywornaway.Alongwiththetechnicalfastfiercelydevelopinelectronics,theelectronicvehiclecanbeappliedextensively.Recently,alotofcarappearanceshavealreadyusedtheelectronicvehicleodometer,thisgraduationthesisintroduceakindofintelligenceelectronicvehicleodometer,whichisbasedonaSingle-ChipMicrocomputersystem.Theelectronics'typevehicleodometerisakindofnumericaltypeappearance,whichmainlyconstitutewithtwoparts,thatisvehiclespeedmeterandodometer,itadoptsthelightsensorthatthesensorhasnocontactmeasure.Itnotonlycanshowthetotalmileagethatvehicledrive,butalsocanshowthestagemileageofaperiodoftime.Moreover,It’scanshowthecarspeed,andtherealizationexceedthespeedlimittoreportandsoon.Italsohastheabilityofstrongerlydevelopagain.Thewayofthisvehicleodometercarryoutisasfollows:throughtheinstalledmeasureplateintheautomobileshaft,usethelightsensortomeasuretherotationalspeedinformation.Underthepulseappearance,itmakethevarietyrotationalspeedchangetothevarietyofthelightflux,afterthatthevarietyofthelightfluxconverttoelectricityquantity.Thenthroughthelightelectricityconvertcomponent,wecanmakethepulsesignalinputtotheSingle-ChipMicrocomputerbythefrequencymeasurecircuit.Thenintermsofthefunctionrelationshipofelectricityquantityandrotationalspeed,wecanrealizethemeasureofrotationalspeed,aftercalculatebytheSingle-ChipMicrocompute,wecanobtaintheinformationofmileageandvehiclespeed.Moreover,ThismileageandvehiclespeedinformationcanbedisplayedbytheLEDmonitor.Andthemileagenumeraloftheelectronics'vehicleodometeraccumulationissavinginEEPROM，whichisnoteasilylost,thedataalsocankeepunderthenoelectricappearance.Keyword：AT89S51Single-ChipMicrocomputer；Odometer；Lightsensor；LED；Memory目录引言………………………………………………………………………11总体设计……………………………………………………………………22系统设计可行性分析…………………………………………………22.1总体设计分析……………………………………………………………………22.2硬件模块…………………………………………………………………………32.3软件模块…………………………………………………………………………63硬件单元电路设计……………………………………………………………………73.1传感器的设计……………………………………………………………………73.2单片机与光电传感器的接口设计……………………………...
