多路温度检测系统的设计_毕业设计(论文)

多路温度检测系统的设计

摘要

随着现代信息技术的飞速发展，温度测量控制系统在工业、农业及人们的日常生活中扮演着一个越来越重要的角色，它对人们的生活具有很大的影响，所以温度采集控制系统的设计与研究有十分重要的意义。本次设计的目的在于学习基于51单片机的多路温度采集控制系统设计的基本流程。本设计采用STC89C52单片机作为数据处理与控制单元，采用温度传感器PT100进行温度的采集把温度的物理量转化为电阻值。然后通过PT100温度变送器把PT100温度传感器的电阻值转化为0-5V的电压值。然后通过PCF8591AD转化模块把变换后的电压值转化为数字量。最终传给单片机系统。此设计有两个按键控制两路温度的显示切换。从而达到多路监测的目的。而且本次设计设有两个LED显示等分别表示正常温度和非正常温度两种形式。正常温度转化为非正常温度的临界值可由键盘设定来达到实际工作的要求。

关键词:单片机，温度传感器，温度变送器，AD转化模块，I2C总线

ABSTRACT

With the rapid development of modern information technology, temperature measurement and control system in industry, agriculture and people's daily life plays an increasingly important role in people's daily life, it has a great impact, so the temperature of the control system design and research are very important. This design aims to study based on 51 single-chip temperature acquisition and control system design of the basic flow. This design adopts STC89C52 chip as the data processing and control unit, with the temperature sensor PT100 gathering the temperature physical quantity into a resistance value. Then through the PT100 temperature transmitter PT100 temperature sensor resistance value into a 0-5V voltage value. Then through PCF8591 AD conversion module to transform the voltage value is converted into digital quantity. Finally to the microcontroller system. This design has two buttons control the two temperature display toggle to achieve the purpose of multi-channel monitoring. And the design of a two LED display respectively expressed in normal temperature and normal temperature two forms. Normal temperature into a normal temperature threshold may by the keyboard set up to achieve the demand of practical work.

Key words: single chip, temperature sensor, temperature transmitter, AD conversion module, Inter－Integrated Circuit

目录

1引言 (1)

1.1 课题研究的背景 (1)

1.2 课题研究的目的和意义 (1)

1.3 本文主要研究内容 (2)

2硬件电路的设计 (3)

2.1 系统设计的框架 (3)

2.2 单片机的选型 (4)

2.2.1STC89C52单片机的简介 (4)

2.2.2STC89C52单片机时序 (4)

2.2.3STC89C52单片机引脚介绍 (5)

2.3 PCF8591AD转化模块 (7)

2.4 PT100温度变送器 (9)

2.5 PT100温度传感器 (11)

2.5.1 设计原理 (11)

2.5.2 应用范围 (11)

2.5.3 分度表 (11)

2.5.4 PT100温度传感器三根芯线的接法： (13)

2.6 LCD1602显示器 (15)

2.7 LED指示灯电路 (23)

2.8 按键电路 (23)

2.9 晶振电路 (24)

3 系统软件设计 (25)

3.1 I2C总线设计 (25)

3.1.1 I2C总线特征 (25)

3.1.2 I2C总线术语 (25)

3.1.3 I2C总线位传输 (25)

3.1.4数据的有效性 (26)

3.1.5 起始和停止条件 (26)

3.1.6 I2C总线数据传输 (27)

3.2总流程图 (28)

结论 (29)

参考文献 (30)

致谢 (31)

附录A：系统原理图 (32)

附录B：系统相关程序 (33)