四川师范大学成都学院电子工程学院课程设计报告I汽车速度里程表的设计摘要：在车辆高速行驶的过程中，车速里程表是为驾驶员及时提供动态驾驶信息的重要仪表，它的好坏直接影响到车辆行驶安全。而传统的车速里程表存在两大缺陷：一是用软轴驱动的传统车速里程表在车辆高速行驶状态下，软轴高速旋转，由于软轴钢丝应力极限的限制，常常造成钢丝软轴的疲劳断裂，从而使车速里程表失效；二是由于软轴布线过长，出现形变过大和运动迟滞现象，导致动态指示迟钝或指示错误。为了更加及时可靠的为驾驶员提供动态驾驶信息，保证车辆行驶安全，客服传统软轴驱动车速里程表故障率高、动态指示迟钝等问题，运用先进的电子技术、传感器测量技术和计算机智能技术，改进传统的里程表是非常必要的。关键字：单片机，霍尔传感器，车速里程表Abstract:Intheprocessofhigh-speedvehicles,vehiclespeedodometerisimportantinstrumentdrivertoprovidedynamicdrivinginformation,whichdirectlyaffectstherunningsafetyofvehicles.Thespeedometertraditionhastwodefects:oneisthetraditionalspeedometerflexibleshaftdrivingthevehiclehighspeedrunningcondition,theshaftrotatingspeed,theflexibleshaftsteelwirestresslimit,oftenresultinginfatiguefractureofthewireflexibleshaft,sothatthespeedometerfailure;twoisaflexiblewiringistoolongduetodeformation,appeartoolargeandthemotionlag,leadtodynamicindicatingsloworindicationerror.Inordertobemorereliableandtimelytothedriver'sdrivingdynamicinformation,guaranteethedrivingsafety,theproblemofhighfailurerate,thespeedometerdynamicindicatingslowservicetraditionalflexibleshaftdriving,theuseofelectronictechnology,sensortechnologyandcomputerintelligencetechnologyadvanced,theimprovementofthetraditionalodometerisverynecessary.Keywords:Themicrocontroller,hallsensors,memory，Thespeedometer四川师范大学成都学院电子工程学院课程设计报告II目录前言...................................................11系统概述.............................................22基本原理与设计方案...................................22.1霍尔传感器简介...........................................32.2AT89C2051芯片简介........................................42.3液晶显示模块SED1520芯片介绍..............................52.3.1SED1520芯片介绍.....................................52.3.2SED1520的特性.......................................62.3.3SED1520指令与显示RAM结构...........................62.4定时器/计数器的结构.......................................72.5定时计数器的原理..........................................72.6频率测量.................................................83系统硬件设计.........................................83.1信号预处理电路...........................................83.2施密特触发器.............................................93.3液晶显示电路和数据存储电路...............................104系统软件设计........................................114.1电机转速控制模块程序设计.................................124.2频率测量模块程序设计.....................................124.3液晶显示程序的设计.......................................154.4速度、里程显示程序的设计.................................154.5模块程序设计............................................185软件调试............................................205.1程序的查错手段..........................................205.2源程序的检测............................................215.3源程序的调试............................................216设计总结............................................22参考文献...........................................
