毕业论文--基于单片机的电子秤的设计与实现.doc

摘 要 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、人性化用在了电子称重的控制系统中。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。 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。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 AT89S52，CZAF-602压力传感器，A/D转换器，LCD显示器. Abstract With the application of microelectronic technology，the tools of traditional weighing on the market have cant satisfy the demands of people. In order to change the problem of the application of traditional weighing tools in the using of daily life, the design will be integrated with intelligence, automation and human nature in the electronic scales with weight control system. This system mainly controlled by the single chip microcomputer , measured by weighting transducer and A/D converter component and added with the display unit, the electronic scales are aptitude for the high ratio of performance, multi-function , low power consumption ,and it is simple enough ,especially it is given the characteristic with Easy-to-use intuitively, Speed, Measure accurately, Higher automation. The system take AT89S52 SCM as the main controller chip, and its peripheral circuit attach to integrated circuit, display circuit, alarm circuit, keyboard circuit which integrate the weighing system circuit board, so the design can realize the automatic weighing system function, alarm function, weighing data calculation function and Man-machine exchange function. We can say that the design of complete electronic scales largely meet the application requirements perfectly. KEYWORDS: AT89S52，CZAF-602 sensor，A/D converter，LCD Display第一章 绪论 1 1.1 研究目的和意义 1 1.2 电子称重系统的应用领域 1 1.3 国内外研究现状、发展动态 2 1.4 主要工作以及论文结构 3 第二章 系统方案论证与选型 4 2.1 控制器部分 4 2.2 数据采集部分 5 2.2.1 传感器的选择 5 2.2.2放大电路选择 8 2.2.3 A/D转换器的选择 11 2.2.4键盘处理部分方案论证 13 2.3显示电路部分的选择 13 2.4超量程报警部分选择 14 第三章 硬件电路设计 15 3.1 AT89S52的最小系统电路 15 3.1.1单片机芯片AT89S52介绍 15 3.1.2.单片机管脚说明 16 3.1.3 AT89S52的最小系统电路构成 19 3.2数据采集部分电路设计 20 3.3显