三、设计任务及要求
设计电压表并实现简单测量。具有以下基本功能：
⑴可以测量0~5V的8路输入电压值；
⑵可在四位LED数码管上轮流显示或单路选择显示；
⑶测量最小分辨率为0.019V；
⑷.测量误差约为±0.02V；
⑸带有一定的扩展功能；
第一章摘要·················4
5.4 A/D采样方案················································10
5.5串口通讯方案···············································12
5.7高压，短路报警·············································14
第一章摘要
本报告介绍了基于AT89S52单片机为核心的、以AD0809数模转换芯片采样、以1602液晶屏显示的具有电压测量功能的具有一定精度的数字电压表。在实现基础功能要求之上扩展了串口通讯、时钟功能、高压报警、短路测试、电阻测量、交流电压峰峰值和周期测试等功能，使系统达到了良好的设计效果和要求。
关键词：AT89S52单片机模数转换液晶显示扩展功能
Keywords : AT89S52 SCM analog-to-digital conversion functions LCD expansion
第二章 智能仪表目前发展状况
在自动化控制系统中，仪器仪表作为其构成元素，它的技术进展是跟随控制系统技术的发展的。常规的自动化仪器仪表适应常规控制系统的要求，它们以经典控制理论和现代控制理论为基础，以控制对象的数学模型为依据。当今，控制理论已发展到智能控制的新阶段，自动化仪器仪表的智能化就成为必然和必须。本文将就自动化仪器仪表的智能化的状况与进展，以及当今对智能仪器仪表研究、开发热点做概要的分析与表述。作者建议人们关注自动化仪器仪表智能化技术的进展，关注仪器仪表装置与控制系统技术的互动发展，这对推进我国自动化技术水平的进一步提高将是大为有益的。智能化的自动化仪器仪表应以智能控制理论为基础，体现人的智能行为。人工智能是智能控制理论的基本组成部分之一，它以知识为基础，它的目标是建造智能化的计算机系统，用来模拟和执行人类的智力功能，如判断、理解、推理、识别、规划、学习和问题求解等等，进而用自动机模仿人类的思维过程和智能行为。基于智能控制理论基础的智能仪器仪表目前大致有几方面的进展:
第八章结果分析···············································19
第九章设计体会··············································19
参考文献························································20
ABSTRACT：The report describes the AT89S52 based on the microcontroller as the core, AD0809 digital-to-analog converter chip sampling, to 1602 LCD display with voltage measurement function with a certain precision of digital voltage meter. In achieving functional requirements based upon the expansion of serial communications, high-pressure alarm, short circuit, electrical resistivity measurement, AC voltage and the peak of cycle testing and other functions, allowing the system to achieve good results and the design requirements.
第二章智能仪表目前的发展状况··························4
第三章设计目的············································6
第四章设计要求············································6
第五章 设计方案与比较论证································6
5.8键盘·······················································14
第六章 方案设计··············································15
6.1硬件设计····················································15
1、设计题目：简易数字电压表的设计
二、设计目的
自动化专业的专业实践课程。本课程的任务是使学生通过“简易数字电压表的设计”的设计过程，综合所学课程，掌握目前自动化仪表的一般设计要求，工程设计方法，开发及设计工具的使用方法，通过这一设计实践过程，锻炼学生的动手能力和分析，解决问题的能力；积累经验，培养按部就班，一丝不苟的工作个对所学知识的综合应用能力。
6.2软件设计····················································16
第七章 性能测试···············································18
电压测试······················································18
5.1单片机电路设计··············································6
5.2电源方案····················································8
5.3显示方案····················································9
附录··························································20
元器件清单················································20
程序清单····················································20