基于AT89C51单片机的应力测试仪的设计

基于AT89C51单片机应力测试仪设计摘要随着自动称量技术的不断发展，传统的模拟称重系统在测量精度、测量功能及性价比都不能满足人们的要求，单片机及集成电路的发展为实现具有良好性能的电子称重系统提供了条件，该课题设计一种由单片机控制的电子称系统，通过压力传感器感应物品重量，并由信号放大处理电路及A/D装换电路转换为电信号，由单片机进行信号的处理与控制，并通过LED进行重量的显示，同时由语音电路实现语音播报。

该电子称设计由称重传感器，前端放大电路，A/D转换电路，单片机控制电路，显示电路，稳压电源等各部分组成。

本设计采用单片机作为最小系统实现电子称的基本控制功能，LM358放大器件、A/D转换芯片ADC0832以及相关称重传感器作为该设计的数据采集部分。

语音部分采用ISD1420语音电路（已烧录），可语音播报所称重量等语音内容。

软件部分采用单片机C语言进行编程，实现了该设计的全部控制功能。

该电子称可以实现基本的称重功能（称重范围为0～3Kg），最小分辨率为0.01Kg，并扩展了语音报数的功能。

整个系统结构简单，使用方便，功能齐全，精度高，具有一定的开发价值。

关键词：单片机称重传感器放大电路A/D转换LED 语音播报AbstractWith the continuous development of automatic weighing technology,traditional analog weighing system in measuring precision,measurement function and price cannot satisfy the requirement of people,microcontroller and the development of integrated circuits with good performance for the realization of electronic weighing system provided a condition,the subject by a single-chip microcomputer control design of electronic scale system,through the pressure sensors,and article weight by amplification processing circuit and A/D conversion into electrical signal installed rewiring by MCU,on signal processing and control,and the weight by LED display,but also achieve speech broadcast by voice circuits.The design of electronic scale is composed by weighing sensor,front-end amplifying circuit,A/D circuit,single-chip microcomputer control circuit,display circuit,manostat and so on various parts. This design uses the monolithic integrated circuit as the smallest system realize electronic scale the basic control function,LM358 amplification device,A/D conversion chip ADC0832 and related weighing transducer as the design of data acquisition parts. Speech part adopts ISD1420 voice circuits (has record),can burn as the weight speech broadcast speech content. Software part adopts single-chip microcomputer C programming language,realize the design of all control function. The electronic scale can realize basic weighing function (weighing the range of 0 ~ 3Kg),minimum resolution is 0.01 Kg,and expanded the voice sound off function. The whole system structure is simple,easy to use,the function is all ready,high precision,has some of the development value.Keywords：MCU weighting sensor amplifier circuit A / D conversion LED V oice Broadcast目录1绪论..................................................................... １1.1本课题的研究背景及意义............................................... １1.2 电子称的发展及研究成果............................................... １1.2.1国内外发展情况.................................................... １1.2.2电子称的发展方向.................................................. ２1.3研究内容及结构安排................................................... ２2 系统总体方案设计......................................................... ４2.1电子称的设计要求..................................................... ４2.2电子称原理及基本思路................................................. ４2.2.1系统工作原理...................................................... ４2.2.2系统设计基本思路.................................................. ４2.3 系统总体设计方案..................................................... ４2.4 传感器的选型......................................................... ５2.5 放大器的选型. (8)2.6 A/D转换器选型...................................................... １０2.7单片机的选型....................................................... １２2.8人机交互部分....................................................... １２2.8.1键盘输入........................................................ １２2.8.2输出显示........................................................ １３2.8.3 语音播报........................................................ １３2.9系统电源........................................................... １５2.10总体实施方案总结.................................................. １６3系统硬件设计........................................................... １８3.1数据采集部分....................................................... １８3.1.1称重传感器...................................................... １８3.1.2信号放大处理.................................................... １９3.1.3信号转换........................................................ １９3.2 单片机控制部分..................................................... １９3.3人机交互部分....................................................... ２３3.3.1键盘............................................................ ２３3.3.2 LED ............................................................. ２３3.3.3语音播报........................................................ ２３4 系统软件设计........................................................... ２５4.1编程语言的选择.................................................... ２５4.2主程序流程图...................................................... ２５4.3子程序流程图...................................................... ２６4.3.1按键子程序...................................................... ２６4.3.2 LED显示子程序.................................................. ２７4.3.3 A/D转换子程序.................................................. ２７4.3.4语音播报子程序.................................................. ２８5电子称称重调试......................................................... ３０结论..................................................................... ３２致谢..................................................................... ３３参考文献................................................................. ３４附录..................................................................... ３５附录1.................................................................. ３５附录2.................................................................. ４３1 绪论1.1 本课题的研究背景及意义在当前社会，物品称重是市场交易中很基本的活动，是商业领域最基本的衡具。