数字温度计的设计

数字温度计的设计

文档编号:ZD1471 文档字数:14491

摘要
随着现代信息技术的飞速发展和传统工业改造的逐步实现。能够独立工作的温度检测和显示系统应用于诸多领域。传统的温度检测以热敏电阻.为温度敏感元件。热敏电阻的成本低，但需后续信号处理电路，而且可靠性相对较差，测温准确度低，检测系统也有一定的误差。
与传统的温度计相比，这里设计的数字温度计具有读数方便，测温范围广，测温精确，数字显示，适用范围宽等特点。选用AT89C51型单片机作为主控制器件，DS18B20作为测温传感器通过4位共阳极LED数码管串口传送数据，实现温度显示。通过DS18B20直接读取被测温度值，进行数据转换，该器件的物理化学性能稳定，线性度较好，在O℃~100℃最大线性偏差小于0．1℃。该器件可直接向单片机传输数字信号，便于单片机处理及控制。另外，该温度计还能直接采用测温器件测量温度，从而简化数据传输与处理过程。

关键词：温度传感器，DS18B20，AT89C51，显示电路, 数字温度计

Abstract
Along with present information technology swift development and traditional industry transformation gradual realization. Can the independent working temperature examination and the display system applies in many domains. Traditional temperature examination take thermistor as temperature sensitive unit. Thermistor's cost is low, but needs the following signal processing electric circuit, moreover the reliability is relatively bad, the temperature measurement accuracy is low, the examination system also has certain error.
Compares with the traditional thermometer, here designs the digital thermometer has the reading to be convenient, the temperature measurement scope is broad, the temperature measurement is precise, the digit demonstrated that applicable scope wide and so on characteristics. Selects at89C51 monolithic integrated circuit to take the master control component, DSl8820 takes the temperature measurement sensor through 4 altogether anode LED nixietube serial port transmission data, realizes the temperature demonstration. Is measured through the DSl8820 direct read the temperature value, carries on the data conversion, this component's physical chemistry stable property, the linearity is good, is smaller than at O℃~100℃ the biggest linear deviation 0.1℃. This component may to the monolithic integrated circuit transmission digital signal, be advantageous for monolithic integrated circuit processing and the control directly. Moreover, this thermometer can also use the temperature measurement component survey temperature directly, thus reduced data transmission and treating processes.

Keywords: Monolithic integrated circuit； Temperature sensor；DS18B20, AT89C51；Display circuit；Digital thermometer

目录
1 绪论 1
1.1 文档选题背景及研究意义 1
1.2 文档研究的内容及方法 1
2 单片机的介绍及选型 3
2.1 单片机的发展和组成 3
2.1.1 单片机的组成 3
2.1.2 MCS－51单片机的引脚描述及片外总线结构 4
2.2 单片机的选型 7
3 传感器的介绍及应用 8
3.1 传感器 8
3.2 传感器的特性 9
3.3 信号处理方式 10
3.3.1 特性补偿 10
3.3.2 运算处理 11
3.4 传感器的分类 12
3.5 温度传感器及其应用 12
3.6 DS18B20温度传感器 13
4 LED显示电路 16
4.1 LED介绍 16
4.2 LED显示 16
4.3 看门狗电路 16
5 系统程序的设计 18
5.1 系统硬件设计方案 18
5.2 温度传感器与单片机的连接 18
5.3 复位信号及外部复位电路 18
5.4 单片机与报警电路 19
5.5 电源电路 19
5.6 软件设计 19
5.7 数据测试 19
5.8 系统软件算法分析 20
5.8.1 主程序 20
5.8.2 读出温度子程序 20
5.8.3 温度转换命令子程序 20
5.8.4 计算温度子程序 21
5.8.5 显示数据刷新子程序 21
6 结束语 23
致谢 25

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