基于温度传感器的数字温度计.

华东交通大学电子测量传感器设计报告

报告题目：基于温度传感器的数字温度计作者姓名：

专业班级：

学号：

指导老师：

时间：2013~2014学年第一学期

摘要

温度控制系统广泛应用于社会生活的各个领域,如家电、汽车、材料、电力电子等,常用的控制电路根据应用场合和所要求的性能指标有所不同, 在工业企业中,如何提高温度控制对象的运行性能一直以来都是控制人员和现场技术人员努力解决的问题。这类控制对象惯性大,滞后现象严重,存在很多不确定的因素,难以建立精确的数学模型,从而导致控制系统性能不佳,甚至出现控制不稳定、失控现象。传统的继电器调温电路简单实用,但由于继电器动作频繁,可能会因触点不良而影响正常工作。控制领域还大量采用传统的PID控制方式,但PID控制对象的模型难以建立,并且当扰动因素不明确时,参数调整不便仍是普遍存在的问题。

采用数字温度传感器DS18B20，因其内部集成了A/D转换器，使得电路结构更加简单，而且减少了温度测量转换时的精度损失，使得测量温度更加精确。数字温度传感器DS18B20只用一个引脚即可与单片机进行通信，大大减少了接线的麻烦，使得单片机更加具有扩展性。由于DS18B20芯片的小型化，更加可以通过单跳数据线就可以和主电路连接，故可以把数字温度传感器DS18B20做成探头，探入到狭小的地方，增加了实用性。更能串接多个数字温度传感器DS18B20进行范围的温度检测。

本文主要介绍了一个基于89C51单片机和DS18B20的测温系统，详细描述了利用数字温度传感器DS18B20开发测温系统的过程，重点对传感器在单片机下的硬件连接，软件编程以及各模块系统流程进行了详尽分析,该系统可以方便的实现实现温度采集和显示，并可根据需要任意设定上下限报警温度，适合于我们日常生活和工、农业生产中的温度测量。

关键词：AT89C51单片机、温度传感器DS18B20

Abstract

Temperature control system is widely applied in various fields of social life, such as household appliances, automobiles, materials, power electronics, the commonly used

control circuit according to the applications and the required performance indicators is different, in the industrial enterprise, how to improve the performance of the temperature control object has been control personnel and the on-site technical personnel to solve the problem. This kind of control object inertia big, serious lag phenomenon, there are many uncertain factors, it is difficult to establish accurate mathematical model, which can lead to poor performance control system, and even control instability, out of control phenomenon. The traditional relay thermal control circuit is simple and practical, but because the relay action is frequent, it may affect by bad contact of the normal work. Control field is a large number of traditional PID control method, but model of PID control object is difficult to establish, and when the disturbance factors is not clear, inconvenient parameter adjustment is still a common problem.

With digital temperature sensor DS18B20, because of its internal integration A/D converter, make the circuit structure more simple, and reduce the precision of temperature measurement conversion loss, make more accurate temperature measurement. Digital temperature sensor DS18B20 a pin can only communicate with MCU, greatly reducing the wiring trouble, this is more extensibility. Due to the miniaturization of DS18B20 chips, more can and main circuit can jump through single cable connection, therefore, can make digital temperature sensor DS18B20 a probe, into a narrow place, increases the practicability. Better combination of multiple digital temperature sensor DS18B20 is used to detect the range of temperature.

This paper mainly introduces a temperature measurement system based on 89 c51 MCU and DS18b20, describes in detail using digital temperature sensor DS18b20 temperature measurement and control system in the development process, focusing on sensor under the single chip microcomputer hardware connection, software programming and the flow diagram of each module system has carried on the detailed analysis, the system can easily realize temperature acquisition and display, and can use either set the upper and lower alarm temperature, suitable for our daily life and temperature measurement in industrial and agricultural production.

[Keywords] STC89C52 microcontroller、DS18B20