毕业论文 高精度温度计.doc

1.1万字 36页

摘 要

【摘要】：在日常生活及工业生产过程中，经常要用到温度的检测及控制，温度是生产过程和科学实验中普遍而且重要的物理参数之一。在生产过程中，为了高效地进行生产，必须对它的主要参数，如温度、压力、流量等进行有效的控制。温度控制在生产过程中占有相当大的比例。温度测量是温度控制的基础，技术已经比较成熟。传统的测温元件有热电偶和二电阻。而热电偶和热电阻测出的一般都是电压，再转换成对应的温度，这些方法相对比较复杂，需要比较多的外部硬件支持。我们用一种相对比较简单的方式来测量。我们采用美国DALLAS半导体公司继DS1820之后推出的一种改进型智能温度传感器DS18B20作为检测元件，温度范围为 -55~125 ºC,最高分辨率可达0.0625 ºC。DS18B20可以直接读出被侧温度值，而且采用三线制与单片机相连，减少了外部的硬件电路，具有低成本和易使用的特点。

本文主要介绍高精度温度计的设计。本设计大体分三个工作过程：首先,由DS18b20温度传感器芯片测量当前的温度,并将结果送入单片机。然后,通过 AT89C51单片机对送来的温度进行计算和转换,并将此结果送入液晶显示模块。最后,由1602液晶显示器将温度显示出来。

【关键词】: 温度控制、温度测试、AT89C51、1602LCD、DS18b20温度传感器

ABSTRAC

【ABSTRAC】:In daily life and industrial production process, often used in the detection and control of temperature, temperature is the production process and scientific experiments in general and one of the important physical parameter. In the production process, in order to efficiently carry out the production, to be its main parameters, such as temperature, pressure, flow control, etc... Temperature control in the production process of a large proportion. Temperature measurement is the basis of temperature-controlled, more mature technology. Traditional thermocouple and temperature components are the second resistor. The thermocouple and thermal resistance are generally measured voltage, and then replaced by the corresponding temperature, these methods are relatively complex, requiring a relatively large number of external hardware support. We use a relatively simple way to measure. We use the United States following DALLAS Semiconductor DS1820 improved after the introduction of a smart temperature sensor DS18B20 as the detection element, a temperature range of -55 ~ 125 º C, up to a maximum resolution of 0.0625 º C. DS18B20 can be directly read out the temperature on the north side, and three-wire system with single-chip connected to a decrease of the external hardware circuit, with low-cost and easy use.

This paper describes the design of high-precision thermometer. This design generally divided into three work process: First of all, the temperature sensor chip by measuring the current DS18b20 temperature, and the results into the microcontroller. Then, by AT89C51 microcontroller sent to the calculation of the temperature and conversion, and this result into the liquid crystal display modules. Finally, by 1602 the temperature LCD display.

【Key words】: Temperature control、temperature testing、 AT89C51、 1602LCD、DS18b20 temperature sensor

目 录

第一章 绪论 1

第二章 系统硬件的设计 2

2.1 硬件设计 2

2.1.1功能要求 2

2.1.2方案论证 2

2.2 系统硬件电路的设计..............................................2

2.2.1 AT89C51单片机 2

2.2.1.1 AT89C51简介及引脚功能说明.......................................2

2.2.1.2 复位电路........................................................4

2.2.1.3 时钟(晶振)电路 4

2.2.2 1602液晶显示器 5

2.2.2.1 1602LCD 基本参数及引脚功能说明..................................5

2.2.2.2 1602LCD 指令说明及时序..........................................6

2.2.2.3 1602LCD 标准字符库..............................................8

2.2.2.4 1602LCD 显示电路图..............................................9

2.2.3 DS18b20 温度传感器........................................10

2.2.3.1 DS18B20 结构及引脚功能说明.....................................10

2.2.3.2 DS18B20 内部结构...............................................10

2.2.3.3 DS18B20 初始化和读/写时序......................................12

2.2.3.4 DS18B20 常用指令...............................................13

2.2.3.5 DS18B20 温度采集电路图.........................................14

第三章 系统程序的设计 15

3.1 主程序 15

3.2 DS18B20模块程序 15

3.3 1602液晶模块程序............................................... 16

第四章 应用的相关软件 18

4.1 keil uVision3编辑软件 18

4.2 Protel 99SE 电路板设计软件 18

4.3 智能高速通用编辑器 18

第五章 实物效果展示 20

第六章 结论与心得 21

致谢 22

参考文献 23

附录A. 高精度温度计电路原理图 24

附录B. 材料清单 25

附录C. 源程序 26