毕业设计（论文）
题 目： 淀粉烘干设备的电控系统设计 学 院： 机电工程学院 专业班级： 机械工程及自动化05级（2）班 指导教师： 职称 学生姓名： 学 号：
摘 要
湿度及湿度的测量和控制对人类日常生活、工业生产、气象预报、物资仓储等都起着极其重要的作用。在许多场合，及时准确获得目标的温度、湿度信息是十分重要的，近年来，温湿度测控领域发展迅速，并且随着数字技术的发展，温湿度的测控芯片也相应的登上历史的舞台，能够在工业、农业等各领域中广泛使用。
针对此领域的发展方向，本文介绍了温湿度自动检测系统。本系统是以AT89S51单片机为控制单元、温度传感器AD590、湿度传感器SHT1100为主要检测器件，实现温度、湿度的测量、显示、报警、保存。本设计使用单片机汇编语言进行设计开发，采用Protel 99SE实现电路的设计要求：温度测量范围为 -30℃～+150℃，精度为±0.5℃；湿度测量范围为：10～100%RH，精度为±2.0%RH；温、湿度越限报警。
本设计包括硬件设计和软件设计,并给出了硬件电路设计原理框图和软件设计流程图。
关键词：单片机，温湿度，A/ D 转换
I
ABSTRACT
The single ship microcomputer is required extensively in measurement and control systems and the temperature and humidity need to be surveyed ,controlled and maintained by a system frequently. Humidity and moisture measurement and control of human daily life, industrial production, weather forecasting, materials storage and so plays a vital role. On many occasions, the objective of timely and accurate access to the temperature and humidity information is very important, in recent years, monitoring and control temperature and humidity fields have developed rapidly, and with the development of digital technology, measurement and control temperature and humidity of the chip also boarded the corresponding stage of history, In industry, agriculture and other fields in widespread use. For this area of development, this paper, based on the temperature, humidity detection system. AT89S51 SCM is the system for the control unit, temperature and humidity sensor SHT1100 as the main detection devices, temperature, humidity measurements, display, alarm and preserve. The design of the C language design, development, use Protel 99SE to achieve the circuit design requirements: temperature measurement range of -30℃~ +150 ℃, accuracy of ± 0.5 ℃; humidity measurement range: 10~ 100% RH, the accuracy of ± 1.0% RH.
The design of temperature and humidity control system on the basis of the 89C51 single chip is introduced , including the design of the hardware and software implementation. The functional block diagram of hardware circuit and software flow chart are given.
KEY WORDS： single chip , temperature and humidity , A/ D transfer
II
西安工程大学本科毕业设计（论文）
目 录
第1章 绪论 ................................................................................................ 1
1.1 选题背景 ....................................................................................................................... 1 1.2 设计过程及工艺要求 ................................................................................................... 2 1.2.1 基本功能 ................................................................................................................ 2 1.2.2 主要技术参数 ........................................................................................................ 2
第2章 方案的比较和论证 ........................................................................ 3
2.1 温度传感器的选择 ....................................................................................................... 3
2.1.1 采用热电阻温度传感器 ........................................................................................ 3 2.1.2 采用AD590温度传感器 ........................................................................................ 3 2.2 湿度传感器的选择 ....................................................................................................... 4 2.2.1 采用HOS-201湿敏传感器 .................................................................................... 4 2.2.2 采用HS1100/HS1101湿度传感器 ........................................................................ 4 2.3 信号采集通道的选择 ................................................................................................... 4 2.3.1 采用多路并行模拟量输入通道 ............................................................................ 5 2.3.2 采用多路分时的模拟量输入通道 ........................................................................ 5
第3章 系统总体设计 ................................................................................ 6
3.1 信号采集 ....................................................................................................................... 6
3.1.1 温度传感器 ............................................................................................................ 6 3.1.2 湿度传感器 .......................................................................................................... 11 3.1.3 多路开关 .............................................................................................................. 13 3.2 信号分析与处理 ......................................................................................................... 14 3.2.1 A/D转换 ............................................................................................................... 14 3.2.2 MC14433与AT89S51单片机的接口设计 ........................................................... 17 3.3 单片机AT89S51 .......................................................................................................... 18 3.3.1 主要特性 .............................................................................................................. 18 3.3.2 内部结构 .............................................................................................................. 19 3.3.3 外部特性（引脚功能） ...................................................................................... 21 3.3.4 工作方式 .............................................................................................................. 22 3.3.5 数据存储器的掉电保护 ...................................................................................... 23 3.4显示与报警的设计 ...................................................................................................... 23 3.4.1 显示电路 .............................................................................................................. 23 3.4.2 报警电路 .............................................................................................................. 24
第4章 软件设计 ...................................................................................... 25 参考文献 .................................................................................................... 36
I