基于单片机的数字测速仪设计.doc

PAGEIV学号：常州大学毕业设计（论文）（2012届）题目学生学院专业班级校内指导教师专业技术职务校外指导老师专业技术职务二○一二年六月基于单片机的数字测速仪设计摘要：在工程实践中，经常会遇到各种需要测量转速的场合，测量转速的方法分为数字式和模拟式两种。模拟式采用测速发电机为检测元件，得到的信号是模拟量。数字式通常采用光电编码器，霍尔元件等为检测元件，得到的信号为脉冲信号。随着微型计算机的广泛应用，特别是高性能价格比的单片机的出现，转速测量普遍采用以单片机为核心的数字式测量方法。本论文描述了一个以AT89S52单片机控制模块、红外传感器采集模块、电机驱动模块和报警模块为主要部分组成的转速测量系统。该系统以一对红外发射和接收二极管形成光路，通过照射到齿盘上颜色的变化对光路形成脉冲，单片机采用同步M/T法对脉冲计数，经过内部数据处理得出转速，并通过1602液晶显示器显示出结果。同时当转速超过其所设定的数值时，系统对其进行报警。通过L298N电路调节电机转速，从而实现在一个电机上对低转速和高转速的测量。关键词：AT89S52单片机；同步M/T法；1602液晶；L298N电路Designofdigitalspeedometerbasedonsingle-chipmicrocomputerAbstract：Inengineeringpractices,thesituationofmeasuringrevolvingspeedoftenoccurs.Therearetwowaystomeasurerevolvingspeed:analogtypeanddigitaltype.Withanalogtype,tachogeneratorisusedasdetectingelement,whichbringsoutanalogquantity,whilewithdigitaltype,photoelectricencoder,Hallelementetc.areoftenused,whichbringsoutpulsesignal.Withthewidespreadofmicrocomputers,especiallyhighlycost-efficientmicrocontroller,weoftenusemicrocontrollerasthecoreofmeasuringrevolvingspeed.ThispaperfocusesondescribingarevolvingspeedmeasuringsystemcomposedbyAT89S52microcontroller(controllingmodule),infraredsensor(collectingmodule),electricalmachine(drivingmodule),andalarmingmodule,whichusesapairofinfraredemitting-and-receivingdiodestoformtheopticalpath.Throughtheintervalblock-outfromthechangeofcolorsonthefluteddisc,electricpulsecanbegenerated.ThemicrocontrollerusessynchronicM/Tmethodtomeasurethetimeofpulse,thenafterinnerdataanalysis,theauthorcangettherevolvingspeedandfinallya1602LCDisusedtoshowtheresult.Whentherevolvingspeedoutstripsthefixednumber,systemalarms.What’smore,throughtheuseofL298circuittoadjusttherevolvingspeedofelectricalmachine,themeasurementoflowandhighrevolvingspeedinginoneelectricalmachinecanberealized.Keywords：MCS52;SynchronicM/Tmethod;1602LCD;L298circuit目录TOC\o"1-3"\h\z\uHYPERLINK\l"_Toc326886542"摘要PAGEREF_Toc326886542\hIHYPERLINK\l"_Toc326886543"目录PAGEREF_Toc326886543\hIIIHYPERLINK\l"_Toc326886544"1引言PAGEREF_Toc326886544