多功能称重系统设计与仿真

摘要本文介绍了基于单片机89C52的电子秤的硬件电路及软件流程。系统包括称重传感器、信号放大、单片机、键盘、LCD显示等部分。电子秤设计得小巧，结构简单，具有去皮、单价设置、累加等多种功能。随着微电子技术的应用，市场上使用的传统称重工具已经满足不了人们的要求。为了改变传统称重工具在使用上存在的问题，在本设计中将智能化、自动化、人性化用在了电子秤重的控制系统中。本系统主要由单片机来控制，测量物体重量部分由称重传感器及A/D转换器组成，加上显示单元，此电子秤俱备了功能多、性能价格比高、功耗低、系统设计简单、使用方便直观、速度快、测量准确、自动化程度高等特点。本系统以AT89S52单片机为主控芯片，外围附以称重电路、显示电路、报警电路、键盘电路等构成智能称重系统电路板，从而实现自动称重系统的各种控制功能。可以说,此设计所完成的电子秤很大程度上满足了应用需求。关键词：单片机；称重传感器；A/D转换器；LCD显示AbstractWiththeapplicationofmicro-electronicstechnology,traditionponderationinstrumentusedinmarkethasbeennotsatisfactionwithhunmanrequirementsalready.Inordertomakeupforthetraditionalapparatusshortcoming,weimprovetheapparatus'scontrolsystemwithintelligenceandautomation.Thissystemismainlycontrolledbymicrocontroller,thesectionofheightmeasurementaccomplishbysupersonicsensor,thesectionofweightmeasurementaccomplishbyweightsensorandA/Dtransformer,thisapparatushavemanycharacteristicsuchashavingmorefunction,consumelessenergy,smallandmoveeasily,lowprice,measureprecisely,thespeedisquick,automaticworkwithoutpeopleandsoon.ThesystemismainlycontrolledbythemicrocontrollerAT89S52,theperipheryisconsistofthecircuitofclockandcalendar,thecircuitofmeasureheightandweight,thecircuitofdisplayandprint,allofthesecomprisethecircuitboardoftheintelligentapparatusofheightandweight.Itcanachieveallfunctionoftheapparatus.KEYWORDS:SP20C-G501，AT89S52，ponderation–sensor，A/Dconverter，LCDDisplay目录摘要.............................................................................................错误!未定义书签。Abstract..............................................................................................................................3引言............................................................................................................................11绪论................................................................................................................................11.1本设计在国内外的研究现状...........................................................................11.2本设计的选题及意义........................................................错误!未定义书签。2总体的方案设计............................................................................................................22.1显示器的选择方案...........................................................................................22.2AD芯片的选择方案........................................................................................22.3CPU的选择方案..............................................................................................32.4总体方案的设计...............................................................................................33硬件设计......................................................................................................................43.1传感器的设计......................................................................................................43.11电阻应变式的组成及原理.......................................................................43.12电阻应变式传感器测量电路的设计.......................................................53.2A/D转换系统的电路设计................................................错误!未定义书签。3.21ADC0809芯片的内部逻辑结构............................错误!未定义书签。3.22ADC0809芯片的外部结构...................................................................73.23ADC0809芯片的使用说明....................................错误!未定义书签。3.24数模转换电路的设计..............................................错误!未定义书签。3.3CPU控制系统电路的设计..............................................................................93.31AT89C52芯片简介................................................................................93.32AT89C52芯片的引脚说明..................................................................103.33单片机控制电路的设计.....................................................................143.4显示系统电路的设计.....................................................................................143.41液晶显示简介.......................................................................................143.42LCD1602结构及引脚功能................................................................153.43显示电路的硬件设计.........................................................................163.5报警电路的设计.............................................................................................174软件设计..................................................................................................................184.1主程序设计.....................................................................................................184.2AD数据采集及处理的设计..........................................................................184.3键盘处理的设计...........................................................................................205仿真及实验调试......................................................................................................226设计总结..................................................................................................................24参考文献..................................................................................................................25附录A主程序设计......................................................