毕业论文

课程设计题目：基于单片机的电热水器控制器设计

学 院：机械与电子工程学院 学生姓名：彭晓武 班 级：080621 学 号：08062137 指导教师：付志坚

2011年11月1日

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摘 要

本文设计的控制器采用AT89S51单片机作为控制核心来设计智能电热水器。本设计也对单片机控制电热水器实现智能化的可能性进行了分析，利用温度传感器、水位检测装置、及模数转换器等来完成本设计。在硬件设计方面，主要对单片机最小系统及其扩展、电源电路、键盘显示及接口电路、模数转换电路、水位及水温检测电路、报警电路进行了详细介绍。还详细介绍了设计中应用到的主要芯片的性能和特点，包括AT89S51、74LS377、DS18B20、ADC0809等。在软件设计方面，采用汇编语言编程，是由于其易于为单片机所识别，执行速度快。最后对软件调试进行了误差分析。

该智能电热水器设计完善，实现方案简单易行。采用软件设计来控制，可以实现智能检测水位及水温，智能加热，并且提高了整机的可靠性及准确性。

关键词：单片机，控制，智能

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ABSTRACT

As technology make a good progress, the applications of single-chip microcomputer become mature all the time. The single-chip microcomputer integrates the various components in a chip, uses the internal bus structure, reduces the connection in different chips, enhanced greatly the reliability and anti-jamming capability. In the development of single-chip microcomputer, due to its excellent cost performance, high integration, small size, high reliability, it has been used as a control center all the time.

Since the birth of single-chip microcomputer, it began to walk into a human’s life, such as washing machines, refrigerators, electronic toys, DMB, which equipped with the single-chip microcomputer, and improved their intelligence, ability. People, who used them, will love them better. The single-chip microcomputer makes human’s life more convenient, comfortable and colorful. As a result, I use single-chip microcomputer to design intelligent electric water heaters.

This paper mainly discusses the intelligent electric water heater how to work. To achieve system goals, in deep analysis of the AT89S51, I made a set of simple and practical control system design. The system is mainly to use single-chip microcomputer to control centers, with specific hardware architecture and the corresponding software design, thus the intelligence of the water heater would become true.

Keywords: single-chip microcomputer, controller, intelligence

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目 录

引言

………………………………………………………………………………………1

第1章 绪论 ……………………………………………………………………………2

1.1 课题的背景 ………………………………………………………………………2 1.2 课题研究的目的及意义 …………………………………………………………2 1.3 国内外的研究状况和成果 ………………………………………………………3

第2章 总体设计方案 ………………………………………………………………4

2.1设计要求 …………………………………………………………………………4 2.2 方案设计 …………………………………………………………………………4

第3章 硬件系统设计 ………………………………………………………………6

3.1 方案验证…………………………………………………………………………6 3.2 硬件系统设计……………………………………………………………………9

3.2.1 电源电路…………………………………………………………………9 3.2.2 键盘/显示接口电路 ……………………………………………………9 3.2.3 报警电路…………………………………………………………………11 3.2.4 模数转换电路……………………………………………………………12 3.2.5 温度检测电路……………………………………………………………13 3.2.6 水位检测电路……………………………………………………………15 3.2.7 时钟电路…………………………………………………………………16 3.2.8 显示模块…………………………………………………………………17 3.2.9 AT89S51功能及特性介绍………………………………………………20

第4章 软件系统设计………………………………………………………………24

4.1 主程序流程框图……………………………………………………………24 4.2 键扫描子程序流程框图……………………………………………………26 4.3 显示子程序流程框…………………………………………………………26 4.4 运行程序流程框图…………………………………………………………27 4.5 软件仿真……………………………………………………………………27

结论与体会………………………………………………………………………………29 致谢 ………………………………………………………………………………………30

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