摘要

温度是表征物体冷却程度的物理量，也是一种最基本的环境参数。在农工业生产及日常生活中，对温度的测量及控制始终占据着极其重要的地位。目前,典型的温度测控系统由模拟式温度传感器、A/D 转换电路和单片机组成。由于模拟式温度传感器输出的模拟信号必须经过A/D 转换环节获得数字信号后才能与单片机等微处理器接口，因而使得硬件电路结构复杂，成本较高。而以DS18B20 为代表的新型单总线数字式温度传感器集温度测量和A/D转换于一体,直接输出数字量，与单片机接口电路结构简单，广泛使用于距离远、节点分布多的场合，具有较强的推广应用价值。

本次设计的水箱水温控制系统采用现在流行的AT89S51单片机，配以DS18B20数字温度传感器，该温度传感器可自行设置温度上下限。单片机将检测到的温度信号与输入的温度上、下限进行比较，由此作出判断是否启动继电器以开启设备。

本设计还加入了常用的液晶管显示及状态灯显示灯常用电路，使得整个设计更加完整，更加灵活。该设计已应用于水箱水温控制系统。

关键词：温度， AT89S51，单片机控制，DS18B20

ABSTRACT

The temperature is attributes the object cooling degree the physical quantity, is also one kind of most basic environment parameter. In the agriculture industrial production and the daily life, is occupying the extremely important status throughout to the temperature survey and the control. At present, the typical temperature observation system by the simulation type temperature sensor, A/D switching circuit and the monolithic integrated circuit is composed. Because the simulation type temperature sensor outputs the simulated signal must obtains the digital signal after A/D transformation link be able with microprocessor connections and so on monolithic integrated circuit, thus causes the hardware circuit structure to be complex, the cost is high. But as representative’s new single main line digital temperature sensor collection temperature survey and A/D transforms take DS18B20 in a body, the direct output digit quantity, is simple with the monolithic integrated circuit interface circuit structure, the widespread use in is away from, the node to distribute many situations far, has the strong promotion application value.

The temperature was designed with the now popular AT89S51 SCM, and with DS18B20 digital temperature sensor, The temperature sensor can set up their own temperature collars. SCM will detect that the temperature of the input signal and temperature, the lower comparisons this judgment whether to activate the relay to open the equipment.

The design also includes commonly used digital display and control state lights commonly used circuit, making the whole design more complete, more flexible. The design has been applied to someone, to someone intelligent temperature control.

Key words：emperature ，AT89S51 ，SCM Control ，DS18B20