基于单片机的温度控制系统毕业设计

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毕业设计

题目：基于单片机的温度控制系统

姓 名 X X X 学 院 电气工程与自动化 专 业 计算机控制技术 指导教师 X X 职 称 助理实验师

2009 年 5 月25日

摘 要

随着国民经济的发展，人们需要对各种加热炉，热处理炉，反应炉和锅炉中 温度进行监测和控制。采用单片机来对他们控制不仅具有控制方便，简单和灵活 性大等优点，而且可以大幅度提高被控温度的技术指标，从而能够大大的提高产品的质量和数量。

为了适应工业控制发展的需要，本文在分析单片机对电加热炉温度控制的基础上，将整个系统分为温度测量、A/D转换、单片机系统、键盘操作系统、温度显示电路、报警电路、D/A转换等若干个功能模块。同时分别阐述其结构体系、工作原理、设计、集成方法以及它们之间的共性和特点。由于温控技术与自动化技术的发展非常迅速，本文一方面结合实际应用经验，力求做到较为系统和全面的介绍系统设计与实施技术；另一方面尽可能反应出温控系统的发展趋势，以及其先进性和实用性。

本设计的控制对象为电加热炉，通过控制加在电阻丝两端电压的工作时间，来对电阻丝输出的平均功率加以控制。以单片机为核心，采用固态继电器控温电路，实现对电炉的自动控制。本文将采用PID控制，阐述了PID控制器的设计，硬件结构和软件设计，实现了一套温度采集和控制的方案。该系统具有硬件成本低，控温精度较高，可靠性好，抗干扰能力强等特点。 关键词：电加热炉；单片机；温度控制；固态继续电器

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目 录

前 言 ···································································································································· 1 第一章 单片机温度控制系统方案简介 ····························································· 2 第二章 单片机的选型 ································································································ 4

2.1 MCS—51单片机内部结构与功能 ······························································· 4

2.2 MCS—51输入/输出端口的结构与功能 ····················································· 5 2.3 MCS—51单片机的引脚及其功能 ······························································· 5 2.4 MCS—51的存储器结构 ················································································ 6 2.4.1 程序存储器 ··································································································· 7 2.4.2 数据存储器 ··································································································· 7 2.5 8031系统扩展计划 ························································································· 8 2.5.1 单片机外总线结构 ······················································································ 8 2.5.2 MCS—51系列单片机的扩展 ·································································· 10 2.5.3 芯片的扩展设计 ························································································ 11

第三章 带有I/O接口和计时器的静态RAM8155 ····································· 13

3.1 8155的结构 ···································································································· 13 3.2 8155的引脚功能 ···························································································· 13 3.3 8155的命令格式与状态字 ·········································································· 15 3.4 8155 I/O端口的应用 ····················································································· 16 3.5 MCS—51和8155的接口方法 ··································································· 16

第四章 ADC0809转换芯片 ·················································································· 17

4.1 ADC0809的引脚 ··························································································· 17 4.2 ADC0809的内部组成 ··················································································· 18 4.3 ADC0809与系统总线的连接 ······································································ 20 4.4 ADC0809与8031的接口 ·························································