温度控制系统的设计外文翻译.docx

毕业设计（论文）外文资料翻译
外文出处： International Conference on Electrical
and Control Engineering
附 件：1.外文资料翻译译文；2.外文原文。
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外文资料内容与设计课题有一定关联，对开展毕业设计有 很好的借鉴和指导意义。译文基本能够表达原文意思，但不是 很顺畅。
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附件1:外文资料翻译译文
温度控制系统的设计
摘要：研究了基于AT89S 51单片机温度控制系统的原理和功能，温度测量单元由 单总线数字温度传感器DS18B 20构成。该系统可进行温度设定，时间显示和保存 监测数据。如果温度超过任意设置的上限和下限值，系统将报警并可以和自动控制 的实现，从而达到温度监测智能一定范围内。基于系统的原理，很容易使其他各种 非线性控制系统，只要软件设计合理的改变。该系统已被证明是准确的，可靠和满 意通过现场实践。
关键词：单片机；温度；温度
I. 导言
温度是在人类生活中非常重要的参数。在现代社会中，温度控制（TC ）不仅用 于工业生产，还广泛应用于其它领域。随着生活质量的提高，我们可以发现在酒店， 工厂和家庭，以及比赛设备。而比赛的趋势将更好地服务于整个社会，因此它具有 十分重要的意义测量和控制温度。
在AT89S51单片机和温度传感器DS18B20的基础上，系统环境温度智能控 制。温度可设定在一定范围内动任意。该系统可以显示在液晶显示屏的时间，并保 存监测数据，并自动地控制温度，当环境温度超过上限和下限的值。这样做是为了 保持温度不变。该系统具有很高的抗干扰能力，控制精度高，灵活的设计，它也非 常适合这个恶劣的环境。它主要应用于人们的生活，改善工作和生活质量。这也是 通用的，因此它可以方便地扩大使用该系统。因此，设计具有深刻的重要性。一般 的设计，硬件设计和软件系统的设计都包括在内。
II. 系统总体设计
该系统硬件包括微控制器，温度检测电路，键盘控制电路，时钟电路，显示， 报警，驱动电路和外部RAM。基于AT89S51单片机，DS18B20的将温度信号传送到数 字信号的检测。和信号发送到微控制器进行处理。最后，温度值显示在液晶12232F。 这些步骤是用来实现温度检测。使用键盘接芯片HD7279在设定温度值，使用微控 制器保持一定的温度，并使用液晶显示的温度控制设定值。此外，时钟芯片DS1302 用于显示时间和外部RAM6264是用来保存监测数据。报警将给予及时蜂鸣器如果温 度超过了上限和下限温度值。
III. 硬件设计
A. 微控制器
在AT89S51单片机是一种低功耗，高性能CMOS 8位4K的系统内可编程闪存字节 微控制器。该设备是采用Atmel的高密度非易失性内存技术，并与业界标准的80C51 指令集和引脚兼容。片上闪存程序存储器可以编程就可以在系统或由传统的非易失 性存储器编程。通过结合在系统灵活的8位CPU集成在一个芯片可编程闪存，Atmel 的单片机AT89S51是一个功能强大的微控制器提供了一个高度灵活的和具有成本效 益的解决方案很多嵌入式控制应用。为了节省监测数据，6264是用来作为外部RAM。 它是一个静态RAM芯片，低功耗具有8K字节的内存。
B. 温度检测电路
温度传感器是该系统的关键部分。达拉斯DS18B20的使用，它支持1 - Wire 总线接，板上专利是在内部使用。所有的传感器部分和转换电路集成在一个晶体 管集成电路像［1］。其测量范围为-55C 125C，在-10°C 85C精度为士 0.5 °C ［2, 3］。由DS18B20的温度采集传输在1 - Wire总线的方式，这种高度提高了系统的 抗干扰，使之适合在恶劣的环境现场温度测量［4］。有两个电源DS18B20的供应方 式。首先是外部电源供给：DS18B20的第一脚连接到地面，第二引脚用作信号线， 三是连接到电源。第二种方式是寄生电源［5］。由于寄生电源会导致硬件电路，软 件控制的难度和芯片的性能下降等，但DS18B2 0的(s)的复杂性，可以连接到I/ O 端的单片机在外部电源供电方式，它更受欢迎。因此，外部电源供应使用，而第 二个接脚连接到引脚P1.3可单片机AT89S51。其实，如果多有被检测，DS18B20的 (S)可以连接到1 - Wire总线。但是，当数超过8,有一个向驾驶和更复杂的软 件设计，以及1 - Wire总线长度的关注。一般而言，这是不超过50米。为了实现 远程控制，该系统可在一个无线之一，旨在打破了 1 - Wire总线长度的限制［6］。
C. LCD显示器电路
液晶显示12232F使用，这可以用来显示字符，温度值和时间，并提供一个友好 的显示界面。该12232F是一个具有8192128 x 32像素的汉字数据库和128个16 x 8 像素的ASCII字符集图形液晶显示。它主要由行驱动器/列驱动器和128 x 32点阵 的充分显示图形，以及7.5 x 2个汉字功能的液晶显示器它是在并行或串行方式 连接到外部CPU［7］O为了节约硬件资源，12232F应以串行方式连接到单片机 AT89S51只有4个输出使用的端。液晶显示屏灰度可以通过调整可变电阻连接的 液晶VLCD的PIN码。CLK是用于传输串行通信时钟。SID是用于传输串行数据。CS 是用来使能控制，液晶显示。L+是用来控制LCD背光电源。
D. 时钟电路
达拉斯DS1302的使用，这是一种高性能，低功耗和实时时钟芯片与RAM。在 DS1302的服务于带有日历时钟系统，用于监测的时间。读取数据的时间由AT89S51 单片机，再由液晶显示处理。另外的时间可以调整键盘。在DS1302的晶体振荡器设 定为32768Hz的，建议的补偿电容是6pF。振荡器的频率较低，所以有可能不连接的 电容器，这不会有很大的不同的时间精度。备用电源可以连接到3.6V的可充电电池。
E. 键盘控制电路
系统中的键盘接 HD7279A的驱动下，它有一个+5 V单电源，这是连接，无需 使用任何有源设备的键盘和显示。根据基本要求和系统功能，只有6个按钮是必要 的。该系统的功能是由输入的数据接收单片机AT89S51。为了节省外部电阻器，1 x 6使用键盘和键盘代码定义为：07h的，0FH，17H条，1FH，27H款，2Fh的。该 命令可以读出通过阅读代码指令。HD7279A是连接到单片机AT89S51的串行模式， 只有4个端的需要。DIG0 DIG5和DP分别列线和六个键是实现键盘监控，解码和 识别关键代码行线端。
F. 报警电路
为了简化电路，调试方便，是一个5V的蜂鸣器自动报警电路中的应用［8］。这 使得软件编程简化。它是由9012 PNP晶体管的基连接到AT89S51单片机的引脚P2.5。 当温度超过上限和下限的值，P2.5输出低电平使晶体管上，然后由一个报警蜂鸣器 定。
G. 驱动电路
一个步进电机作为驱动装置来控制温度。四相和八打脉冲分配模式是用来驱动 电机和简单的延时程序是用来处理脉冲之间的时间间隔，获得不同的转速。有两个 步进电机的输出状态。一：当温度超过上限值时，电机反向旋转（以低的温度）， 而当低于下限值时，电机旋转正常（提高温度），除了不等于预设值。二：当温度 在两者之间的某处结束，等于设定值时，电机停止。这些步骤是用来实现温度控制。 此外，电机的转速也可以调整相对按钮。代码数据是通过港答11 A8的输入（P2.3 P2. 0的是）的逆变器74LS04由AT89S51单片机和反向输出。最后，它被放大功 放2803A权力电机。
IV. 软件设计
按照一般设计要求，该系统的硬件电路原理，以及该程序的可读性，可移植性 和改进的调试方便，软件设计模块化。系统流程主要包括以下8个步骤：POST（加 电自检），系统启动，温度检测，报警处理，温度控制，时钟芯片DS1302的操作， 液晶显示和键盘操作。给一点分析，上述8个任务，很容易地发现，过去五年任务 需要实时操作。但对温度的检测，可与TIMER0计时1秒，即出现温度检测达到每秒。 系统启动包括全局变量的定义，内存启动，启动特殊功能寄存器和外围设备的启动。 全局变量的定义，主要完成对外部接连接到单片机AT89S51芯片，内存单位和一 些特殊的定义的接定义。开始主要是指RAM的内存处理。例如，当系统通电时间 码将在内部单位地址或闪烁标志存储的信息将被清除。特殊功能寄存器包括加载启 动定时器初值的开放中断。例如，当系统通电定时器初始化。外围设备的启动，是 指设置外围设备的初始值。例如，当系统通电后，LCD应该被初始化，启动显示器 应该叫，温度转换命令时，必须先发出的时钟芯片DS1302也要被初始化。报警处理 主要是降低和温度的提高使温度保持在预设范围。当温度之间的上限和下限的值， 这是不言而喻的温度控制处理，即需要的温度升高或降低根据预设值。这样做的条 件温度等于设定值，从而达到温度的目标。
V. 结论
温度控制系统具有友好的人机交互界面，硬件简单，成本低，温度控制精度高 （误差在±1°C范围内误差），便利性和多功能性等，它可广泛的场合使用的优点与 -55C至125C范围内，且有一定的实用价值。
附件2：外文原文
Design of the Temperature Control System Based on AT89S51
ABSTRACT
The principle and functions of the temperature control system based on microcontrol AT89S51 are studied, and the temperature measurement unit consists of the 1-Wire bu digitalemperaturesensorDS18B20. The system can be expectedto detectthe preset temperature, display time and save monitoring data. An alarm will be given by system the temperature exceeds the upper and lower limit value of the temperature which can set discretionariahyd then automaticcontrolis achieved, thus the temperatureis achieved monitoringintelligentwlythina certairrange. Basing on principlef the system, it is easy make a varietf other non-lineartrokystemsso longas the sof twarelesigni s reasonably changed.The system has been proved to be accurate, reliable and satisfied through fieldpractice.
KEYWORDS: AT89S51; microcontroller; DS18B20; temperature
I. INTRODUCTION
Temperature is a very importantparameter in human life.In the modern society, temperature control (TC) is not only used in industrial production, but also widely in other fields. With the improvement of the life quality, we can find the TC applia hotels,factorieasnd home as well.And the trendthatTC willbetterserve the whole society, so it is of great significance to measure and controlthe temperature.
Based on the AT89S51 and temperaturesensor DS18B20, thissystem controlsthe conditioitemperatur^ntelligentTlye temperaturecan be setdiscretionar wli^thina certairrange.The system can show the time on LCD, and save monitoringdata;and automatically control the temperature when the condition temperature exceeds the upp and lower limit value. By doing so it is to keep the temperature unchanged. The syst of high ant i-jamming, high control precision and flexible design; i t also fits the environment. It is mainly used in people's life to improve the quality of the work ai It is also versatile, so that it can be convenient to extend the use of the syste designisof profound importance.The generaldesign,hardware designand software design of the system are covered.
II. SYSTEM GENERAL DESIGN
The hardware block diagram of the TC is shown in Fig. 1. The system hardware include the microcontroller, temperature detection circuit, keyboard control circuit, clock Display, alaridrivecircuit and exteRAMl Based on the AT89S51,the DS18B20 will transfer the temperature signal detected to digital signal. And the signal is s， microcontrollfior processingAt lastthe temperature/alue is showed on the LCD 12232F. These steps are used to achieve the temperature detection. Using the keyboa interface chip HD7279 to set the temperature value, us ing the microcontroller to ke certaiitemperatureand using the LCD to show the presetvaluefor controllinghe temperature. In addition, the clock chipisDSL1s3djt2 to show t ime and the external
RAM 6264 is used to save the monitoring data. An alarm will be given by buzzer in ti if the temperature exceeds the upper and lower limit value of the temperature.
III. HARDWARE DESIGN
A. Microcontroller
The AT89S51 is a low-power, high-performancCMOS 8-bitmicrocontrollwith 4K bytes of in-systemprogrammable Flash memory. The device is manufactured using Atmel’shigh-densitynonvolatileiemory technologyand is compatiblewith the industry-standa&0C51 instructiosiet and pinout. The on-chip Flash allows the program memory to be reprogrammed in-systemor by a conventionalnonvolatile memory programmer. By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithicchip, the Atmel AT89S51 is a powerfulmicrocontrolleTiich provides a highly-flexibheid cost-effectisolutionto many embedded control applications. Minimum system of the microcontroller is shown in Fig. 2. In order to monitoringdata, the 6264 is used as an externalRAM. It is a stati(RAM chip, low-power with 8K bytes memory.
B. Temperature Detection Circuit
The temperature sensor is the key part in the system. The Dallas DS18B20 is used, wh: supports the 1-Wire bus interface, and the ON-BOARD Patented is used internally. A the sensorpartsand the converting^ircuiare integratedn integratedircuilikea transistor [1]. Its measure ranogb i1s25-5°G, and the precision betweehOC
85 C is ±0.5C [2 , 3]. The temperature collected by the DS18B20 is transmitted in the 1-Wire bus way, and this highly raises the system ant i-jamming and makes i t f i s i tu temperature measurement of the rugged environment [4].
There are two power supply ways for the DS18B20. The first is external power supply the first pin of the DS18B20 is connected to the ground; the second pin serves as s wire and the third is connected to the power. The second way is parasite power supp As the parasi tpower supply willleadto the complexityof the hardware circuitt,he difficulty of the software control and the performance degradation of the chip, et the DS18B20 (s) can be connected to the I/O port of the microcontroller in the exte power supply way and it is more popular. Therefore the external power supply is us and the second pin is connected to the pin P1. 3 of theA(AtT89S151,. if there are multipoint to be detected, the DS18B20(s) can be connected to the 1-Wire bus. But wh the number is over 8, there is a concern to the driving and the more complex softv design as well as the lengthof the 1-Wire bus. Normally itisno more than 50m. To achievedistanbontrolthe system can be designedin to a wirelessone to break the length limit of the 1-Wire bus [6].
C. LCD Circuit
The LCD 12232F i s used, which can be used to show characters, temperature value and time, and supply a friendly display interface. The 12232F is a LCD w32th 8192 128 x pixels Chinese character database and 8L2{8ixLe)lx ASCI I character set graphics. 11 mainly consists of row drive/column drive andful8xlattice LCD with the function of displaying graphics as well 2aCh7Lnfese characters. It is in a parallell mode to connect to external CPU [7]. In order to economize the hardware resource, 1 12232F should be connectedto the AT89S51 in serialmode with only 4 outputports
used.
The LCD grayscale can be changed by adjus ting the variable resistor connected the p Vlcd of the LCD. CLK is used to transmi t serial communication clock. SID is used 1 transmit serial data. CS is used to enable control the LCD. L+ is used to control th backlight power
D. Clock Circuit
The Dallas DS1302 is used, which is a high performance, low-power and real-time cloc chipwith RAM. The DS1302 servesin the systemwith calendaiclock and isused to monitor the time. The time data is read and processed by the AT89S51 and then display by the LCD. Also the time can be adjusted by the keyboard.
The DS1302 crystaoscillatis setat 32768Hz, and the recommended compensation capacitancis 6pF. The oscillatfrequencyis lower,so itmight be possibloiot to connect the capacitor, and this would not make a big difference to the time precision. backup power supply can be connected to a 3.6V rechargeable battery.
E. Keyboard Control Circuit
The keyboard interfacein the system is drivenby the HD7279A which has a +5V single power supply and which is connected to the keyboard and display without usi any active-device. According to the basic requirements and functions of the system, 6 buttonsare needed. The system'sfunctionsire set by the AT89S51 receiving±e entereddata. In orderto save the externa tesistotjie 1^6 keyboard isused, and the keyboard codes are def ined as: 07H, 0FH, 17H, 1FH, 27H, 2FH. The order can be read out by reading the code instruction. HD727®Annected tohe AT89S51 inserial mode and only 4 portsare need. As shown in Fig. 6, DIG0 DIG5 and DP are respectively the column lines and row line ports of the six keys which achieve keyb monitoring, decoding and key codes identification.
F. Alarm Circuit
In order to simplify the circuit and convenient debugging, a 5V automatic buzzer is in the alarm circuit [8]. And this make the software programming simplified. As shown Fig. 7, it is controlled by the PNP transistor 9012 whose base is connected to the p of theAT89S51. When the temperatur够xceeds the upper and lower limitvalue,the
P2.5 output low level which makes the transistor be on and then an alarm is given by buzzer.
G. Drive Circuit
A step motor is used as the drive device to control the temperature. The four-phase eight-beat pulse distribution mode is used to drive motor and the simple delay progr used to handle the time interval between the pulses to obtain different rotational There are two outputstatefor thestepmotor. One: when the temperatur^sover the upper value, the motor rotates reversely (to low the temperature), while when lower the lower limi t value, the motor rotates normally (to raise the temperature); besic equalsthepresetvalue.Two: when the temperatur^sat somewhere between the two ends and equals the preset value, the motor stops. Tahreeseusetdeptso achieve the temperature control. In addition, the motor speed can also be adjusted by relative b As shown in Fig. 8, the code data is input through ports A11 A8 (be P2. 3 P2. 0) of 1 AT89S51 and invertecbutputby the inverte74LS04. Finallyitis amplifiedby the
power amplifier 2803A to power the motor.
IV. SOFTWARE DESIGN
According to the general design requirement and hardware circuit principle of the sy; as well as the improvement of the program readability, transferability and the conve debugging, the softwaredesignismodularized.The system flow mainly includesthe following^ steps:POST (Power-on self-tes s)y,stem initiatiotemperatur就etection, alarmhandling, temperature conclock chiDS1302 operation^CD and keyboard operation. The main program flow is shown in Fig. 9. Give a little ahaVysis to the 8 tasks, it is easy to find out that the last five tasks require the real time opera the temperature detection i t can be achieved with t imer0 t iming 1 second, that is temperature detection occurs per second. The system initiation includes global vari definition, RAM initiation, special function register initiation and peripheral equ initiation. Globarliable def inition mainly f inishes the interf ace def inition of exte： interface chip connectedtHe) AT89S51, and special definition of some memory units.
RAM initiatiomnainly refersto RAM processing.For example when the system is electrified the time code will be stored in the internal unit address or the scintil will be cleared. The special function register initiation includes loading the init of timer and opening the interrupt. For example, when the system is electrified the is initializeKhe periphera equipment initiaticnefersto set the initiavalue of peripheraequipment.For example, when the systemlectrified, LtHDb should be initialized, tshteart-up display should be called, the temperature conversion command should be issued firstly and the clock chip DS1302 should also be initialized. The handling is mainly the lowering and the raising of temperature to make the temperat remain with the preset range. When the temperature is between the upper and the low limit value, it goes to temperature control handling, that is to say the temperature be raisedor lowered accordingto