外文翻译基于单片机的智能电风扇控制系统(外文原文+中文翻译)

单片机控制系统外文翻译Microcomputer SystemsElectronic systems are used for handing information in the most general sense; this information may be telephone conversation, instrument read or a company’s accounts, but in each case the same main type of operation are involved: the processing, storage and transmission of information. in conventional electronic design these operations are combined at the function level; for example a counter, whether electronic or mechanical, stores the current and increments it by one as required. A system such as an electronic clock which employs counters has its storage and processing capabilities spread throughout the system because each counter is able to store and process numbers.Present day microprocessor based systems depart from this conventional approach by separating the three functions of processing, storage, and transmission into different section of the system. This partitioning into three main functions was devised by Von Neumann during the 1940s, and was not conceived especially for microcomputers. Almost every computer ever made has been designed with this structure, and despite the enormous range in their physical forms, they have all been of essentially the same basic design.In a microprocessor based system the processing will be performed in the microprocessor itself. The storage will be by means of memory circuits and the communication of information into and out of the system will be by means of special input/output(I/O) circuits. It would be impossible to identify a particular piece of hardware which performed the counting in a microprocessor based clock because the time would be stored in the memory and incremented at regular intervals but the microprocessor. However, the software which defined the system’s behavior would contain sections that performed as counters. The apparently rather abstract approach to the architecture of the microprocessor and its associated circuits allows it to be very flexible in use, since the system is defined almost entirely software. The design process is largely one of software engineering, and the similar problems of construction and maintenance which occur in conventional engineering are encountered when producing software.The figure1.1 illustrates how these three sections within a microcomputer are connected in terms of the communication of information within the machine. The system is controlled by the microprocessor which supervises the transfer of information between itself and the memory and input/output sections. The external connections relate to the rest (that is, the non-computer part) of the engineering system.Fig.1.1 Three Sections of a TypicalMicrocomputerAlthough only one storage section has been shown in the diagram, in practice two distinct types of memory RAM and ROM are used. In each case, the word ‘memory’ is rather inappropriate since a computers memory is more like a filing cabinet in concept; information is stored in a set of numbered ‘boxes’ and it is referenced by the serial number of the ‘box’ in question.Microcomputers use RAM (Random Access Memory) into which data can be written and from which data can be read again when needed. This data can be read back from the memory in any sequence desired, and not necessarily the same order in w hich it was written, hence the expression ‘random’ access memory. Another type of ROM (Read Only Memory) is used to hold fixed patterns of information which cannot be affected by the microprocessor; these patterns are not lost when power is removed and are normally used to hold the program which defines the behavior of a microprocessor based system. ROMs can be read like RAMs, but unlike RAMs they cannot be used to store variable information. Some ROMs have their data patterns put in during manufacture, while others are programmable by the user by means of special equipment and are called programmable ROMs. The widely used programmable ROMs are erasable by means of special ultraviolet lamps and are referred to as EPROMs, short for Erasable Programmable Read Only Memories. Other new types ofdevice can be erased electrically without the need for ultraviolet light, which are called Electrically Erasable Programmable Read Only Memories, EEPROMs.The microprocessor processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling special hardware such as disc drives or controlling information transmission to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carried out without directly involving the main microprocessor.The microprocessor , memory and input/output circuit may all be contained on the same integrated circuit provided that the application does not require too much program or data storage . This is usually the case in low-cost application such as the controllers used in microwave ovens and automatic washing machines . The use of single package allows considerable cost savings to e made when articles are manufactured in large quantities . As technology develops , more and more powerful processors and larger and larger amounts of memory are being incorporated into single chip microcomputers with resulting saving in assembly costs in the final products . For the foreseeable future , however , it will continue to be necessary to interconnect a number of integrated circuits to make a microcomputer whenever larger amounts of storage or input/output are required.Another major engineering application of microcomputers is in process control. Here the presence of the microcomputer is usually more apparent to the user because provision is normally made for programming the microcomputer for the particular application. In process control applications the benefits lf fitting the entire system on to single chip are usually outweighed by the high design cost involved, because this sort lf equipment is produced in smaller quantities. Moreover, process controllers are usually more complicated so that it is more difficult to make them as single integrated circuits. Two approaches are possible; the controller can be implemented as a general-purpose microcomputerrather like a more robust version lf a hobby computer, or as a ‘packaged’ system, signed for replacing controllers based on older technologies such as electromagnetic relays. In the former case the system would probably be programmed in conventional programming languages such as the ones to9 be introduced later, while in the other case a special-purpose language might be used, for example one which allowed the function of the controller to be described in terms of relay interconnections, In either case programs can be stored in RAM, which allows them to be altered to suit changes in application, but this makes the overall system vulnerable to loss lf power unless batteries are used to ensure continuity of supply. Alternatively programs can be stored in ROM, in which case they virtually become part of the electronic ‘hardware’ and are often referred to as firmware.More sophisticated process controllers require minicomputers for their implementation, although the use o f large scale integrated circuits ‘the distinction between mini and microcomputers, Products and process controllers of various kinds represent the majority of present-day microcomputer applications, the exact figures depending on one’s i nterpretation of the word ‘product’. Virtually all engineering and scientific uses of microcomputers can be assigned to one or other of these categories. But in the system we most study Pressure and Pressure Transmitters. Pressure arises when a force is applied over an area. Provided the force is one Newton and uniformly over the area of one square meters, the pressure has been designated one Pascal. Pressure is a universal processing condition. It is also a condition of life on the planet: we live at the bottom of an atmospheric ocean that extends upward for many miles. This mass of air has weight, and this weight pressing downward causes atmospheric pressure. Water, a fundamental necessity of life, is supplied to most of us under pressure. In the typical process plant, pressure influences boiling point temperatures, condensing point temperatures, process efficiency, costs, and other important factors. The measurement and control of pressure or lack of it-vacuum-in the typical process plant is critical.单片机控制系统广义地说，微型计算机控制系统（单片机控制系统）是用于处理信息的，这种被用于处理的信息可以是电话交谈，也可以是仪器的读数或者是一个企业的帐户，但是各种情况下都涉及到相同的主要操作：信息的处理、信息的存储和信息的传递。

基于单片机的智能风扇系统设计郑安豫【摘要】The current market sales of electric fans can only manually set the speed.If user fall in sleep when electric fan is on,with the changes in the environment,may lead to sleep discomfort,or even make people sick. Aiming at shortcomings of the electric fan,a Smart fan system that automatically adjusts the speed based on somatosensory temperature is proposed.Get the temperature through the temperature and humidity sensor,calculate the wind speed required for the comfort of the somatosensory temperature by means of temperature and humidity, calculate the fan speed according to the wind speed and design the software to control the fan motor speed,to achieve automatic,real-time adjustment of the fan speed effect.%当前市场上销售的电风扇只能手动设置转速.如果电风扇开启状态下使用者进入睡眠状态,随着环境的变化,轻则导致睡眠不适,重则使人生病感冒.针对电风扇的这些缺点,提出了一种基于体感温度的自动调整转速的智能风扇系统.系统通过传感器获取环境数据(温度、相对湿度),根据体感温度的舒适度模型,通过环境数据计算出人体舒适所需要的风速,根据风速控制单片机输出PWM,利用PWM来实现控制风扇电机的转速,以达到自动、实时调整风扇转速的效果.【期刊名称】《商丘师范学院学报》【年(卷),期】2018(034)003【总页数】3页(P33-35)【关键词】体感温度;温湿度传感器;智能风扇【作者】郑安豫【作者单位】安徽电气工程职业技术学院电力系,安徽合肥230051【正文语种】中文【中图分类】TP271+.40 引言随着科技的发展，人们对家居的智能化与自动化要求也不断提高.电风扇作为一种常用的夏季降暑家用电器，除了简单的转速设定与定时功能，没有其他功能设置选项，已经无法满足使用者的需求.智能风扇的设计进入研究者的视线.智能风扇的设计，一般都是基于环境温度来实现[1-2]的，随着环境温度的变化，控制风扇转速，以实现风扇的智能化.然而实际环境中，影响人体舒适度的，除了温度外，湿度扮演了另一个十分重要的角色；夏季中，温度不是特别高的情况下，如果相对湿度很高，会感觉闷热，十分不适.本文提出了一种基于体感温度的智能风扇系统，实现了风扇转速的自动控制，环境数据、风扇转速液晶显示.弥补了一般智能风扇的只基于环境温度，忽视相对湿度的缺点，提高了使用者的舒适度.1 背景1.1 体感温度体感温度，是指人体通过感觉器官，主要是皮肤对外界环境温度的感受.体感温度往往与实际测量的温度有偏差.它除了受环境温度的影响外，还受其他因素，如相对湿度、风速、太阳辐射的影响[3].仅考虑气象条件的影响下，体感温度的计算方法如下[3]:Tg=Ts+T(u)+T(v)+T(r)其中，Tg为体感温度，Ts为环境温度，T(u)为相对湿度修正项，T(v)为风速修正项，T(r)为太阳辐射修正项[3].由于本文只考虑风扇的使用场景，风扇都在室内使用，所以太阳辐射的修正可以忽略.关于T(u)与T(v)计算方法，有大量文献提出了不同的计算方法[3-6].由于风扇是用来在炎热的夏季提升人体舒适度的工具，本文采用了基于人体舒适度的体感温度计算模型[6].1.2 温湿度传感器本系统采用的温湿度传感器是一款已校准数字信号输出的DHT11数字温湿度传感器.传感器包括一个电阻式感湿元件和一个NTC测温元件.该产品具有响应快速、抗干扰能力强、性价比高等优点[7].2 系统设计为了实现温度、湿度数据收集、转速计算、风扇控制等一系列动作的智能化，需要中央处理器来处理，本系统中采用C51单片机作为中央处理器.为了实现内部数据(温度、湿度、风扇转速)的可视化，系统设计中添加了液晶显示器来显示各项数据. 系统设计如图1所示.图1 系统设计结构图单片机：由于本设计中，对单片机没有特殊要求，基于软件程序的大小，所以选用AT89C54.单片机引脚如图2所示.图2 AT89C54图3 手动复位电路复位电路：单片机的复位电路一般有分为上电复位，手动复位.上电复位指单片机在上电瞬间，给复位引脚一个复位信号(一定时间的高电平或者低电平)，以实现单片机的复位，待稳定后，单片机开始执行程序；手动复位指在单片机的复位引脚接一个按键，手动按下该按键使单片机复位.本文设计中采用手动复位，风扇通电时，给单片机复位，发生故障时，能够手动重置单片机状态.手动复位电路图如图3所示晶振电路：单片机工作时钟需要晶体振荡器提供工作脉冲信号，脉冲频率决定了单片机工作速度.晶振电路如图4所示.液晶显示：采集的温度、湿度、以及现在的风扇转速，通过液晶显示屏显示.风扇驱动：风扇驱动采用PWM(Pulse Width Modulation)控制直流电机的转速.由于C51单片机中没有PWM输出功能，本系统中采用定时器与软件控制来实现PWM的输出[8].图4 晶振电路图5 软件流程图3 软件流程单片机的软件设计流程如图5所示.1)获取环境参数单片机通过温湿度传感器，获取环境温度与湿度；2)计算风扇转速根据获取的环境参数，计算出舒适体感温度需要的理想风速.3)控制风扇转速根据理想风速，计算出风扇的转速4)延时两次计算间的延时间隔4 小结针对普通电风扇的缺点，本文提出了一种基于体感温度的智能风扇设计方案.通过传感器实时获取环境温度与湿度，计算出合适的风扇转速；通过单片机自动控制风扇转速.该设计能够根据环境的变化，自适应地控制风扇转速，达到风扇智能化的目的.参考文献：[1]陈富忠，翁桂琴.智能温控调速风扇的设计[J].上海电机学院学报，2009(04):297-300.[2]李娣娜，王洋.一种简易温控智能风扇控制系统的设计[J].现代电子技术，2012(21):119-120.[3]陈莉，张海东，王承伟，等.体感温度客观分析方法研究[J].成都信息工程学院学报，2009(03):279-284.[4]刘梅，于波，姚克敏.以热量平衡为基础的体感温度模型及气候要素的效应分析[J].南京气象学院学报，2001(04):527-535.[5]王远飞，沈愈.上海市夏季温湿效应与人体舒适度[J].华东师范大学学报(自然科学版)，1998(03):60-66.[6]马盼，王式功，张志薇，等.基于“黄金分割率”的体感温度计算方法及相应舒适度划分[C].创新驱动发展，提高气象灾害防御能力—S15气候环境变化与人体健康[A].2013-10-22.[7]倪天龙.单总线传感器DHT11在温湿度测控中的应用[J].单片机与嵌入式系统应用，2010(6):60-62.[8]吴育军.单片机PWM控制直流电机技术[J].通讯世界，2016(17)：253-254.。

Temperature Control Using a Microcontroller:An Interdisciplinary Undergraduate Engineering Design ProjectJames S. McDonaldDepartment of Engineering ScienceTrinity UniversitySan Antonio, TX 78212AbstractThis paper describes an interdisciplinary d esign project which was done under the author’s supervision by a group of four senior students in the Department of Engineering Science at Trinity University. The objective of the project was to develop a temperature control system for an air-filled chamber. The system was to allow entry of a desired chamber temperature in a prescribed range and to exhibit overshoot and steady-state temperature error of less than 1 degree Kelvin in the actual chamber temperature step response. The details of the design developed by this group of students, based on a Motorola MC68HC05 family microcontroller, are described. The pedagogical value of the problem is also discussed through a description of some of the key steps in the design process. It is shown that the solution requires broad knowledge drawn from several engineering disciplines including electrical, mechanical, and control systems engineering.1 IntroductionThe design project which is the subject of this paper originated from a real-world application.A prototype of a microscope slide dryer had been developed around an OmegaTM modelCN-390 temperature controller, and the objective was to develop a custom temperature control system to replace the Omega system. The motivation was that a custom controller targeted specifically for the application should be able to achieve the same functionality at a much lower cost, as the Omega system is unnecessarily versatile and equipped to handle a wide variety of applications.The mechanical layout of the slide dryer prototype is shown in Figure 1. The main element of the dryer is a large, insulated, air-filled chamber in which microscope slides, each with a tissue sample encased in paraffin, can be set on caddies. In order that the paraffin maintain the proper consistency, the temperature in the slide chamber must be maintained at a desired (constant) temperature. A second chamber (the electronics enclosure) houses a resistive heater and the temperature controller, and a fan mounted on the end of the dryer blows air across theheater, carrying heat into the slide chamber. This design project was carried out during academic year 1996–97 by four students under the author’s supervision as a Senior Design project in the Department of Engineering Science at Trinity University. The purpose of this paper isto describe the problem and the students’ solution in some detail, and to discuss some of the pedagogical opportunities offered by an interdisciplinary design project of this type. The students’ own report was presented at the 1997 National Conference on Undergraduate Research [1]. Section 2 gives a more detailed statement of the problem, including performance specifications, and Section 3 describes the students’ design. Section 4 makes up the bulk of the paper, and discusses in some detail several aspects of the design process which offer unique pedagogical opportunities. Finally, Section 5 offers some conclusions.2 Problem StatementThe basic idea of the project is to replace the relevant parts of the functionality of an Omega CN-390 temperature controller using a custom-designed system. The application dictates that temperature settings are usually kept constant for long periods of time, but it’s nonetheless important that step changes be tracked in a “reasonable” manner. Thus the main requirements boil down to·allowing a chamber temperature set-point to be entered,·displaying both set-point and actual temperatures, and·tracking step changes in set-point temperature with acceptable rise time, steady-state error, and overshoot.Although not explicitly a part of the specifications in Table 1, it was clear that the customer desired digital displays of set-point and actual temperatures, and that set-point temperature entry should be digital as well (as opposed to, say, through a potentiometer setting).3 System DesignThe requirements for digital temperature displays and setpoint entry alone are enough to dictate that a microcontrollerbased design is likely the most appropriate. Figure 2 shows a block diagram of the students’ desig n.The microcontroller, a MotorolaMC68HC705B16 (6805 for short), is the heart of the system. It accepts inputs from a simple four-key keypad which allow specification of the set-point temperature, and it displays both set-point and measured chamber temperatures using two-digit seven-segment LED displays controlled by a display driver. All these inputs and outputs are accommodated by parallel ports on the 6805. Chamber temperature is sensed using apre-calibrated thermistor and input via one of the 6805’s analog-to-digital inputs. Finally, a pulse-width modulation (PWM) output on the 6805 is used to drive a relay which switches line power to the resistive heater off and on.Figure 3 shows a more detailed schematic of the electronics and their interfacing to the 6805. The keypad, a Storm 3K041103, has four keys which are interfaced to pins PA0{ PA3 of Port A, configured as inputs. One key functions as a mode switch. Two modes are supported: set mode and run mode. In set mode two of the other keys are used to specify the set-point temperature: one increments it and one decrements. The fourth key is unused at present. The LED displays are driven by a Harris Semiconductor ICM7212 display driver interfaced to pins PB0{PB6 of Port B, configured as outputs. The temperature-sensing thermistor drives, through a voltage divider, pin AN0 (one of eight analog inputs). Finally, pin PLMA (one of two PWM outputs) drives the heater relay.Software on the 6805 implements the temperature control algorithm, maintains the temperature displays, and alters the set-point in response to keypad inputs. Because it is not complete at this writing, software will not be discussed in detail in this paper. The control algorithm in particular has not been determined, but it is likely to be a simple proportional controller and certainly not more complex than a PID. Some control design issues will be discussed in Section 4, however.4 The Design ProcessAlthough essentially the project is just to build a thermostat, it presents many nice pedagogical opportunities. The knowledge and experience base of a senior engineering undergraduate are just enough to bring him or her to the brink of a solution to various aspects of the problem. Yet, in each case, realworld considerations complicate the situation significantly.Fortunately these complications are not insurmountable, and the result is a very beneficial design experience. The remainder of this section looks at a few aspects of the problem which present the type of learning opportunity just described. Section 4.1 discusses some of the features of a simplified mathematical model of the thermal properties of the system and how it can beeasily validated experimentally. Section 4.2 describes how realistic control algorithm designs can be arrived at using introductory concepts in control design. Section 4.3 points out some important deficiencies of such a simplified modeling/control design process and how they can be overcome through simulation. Finally, Section 4.4 gives an overview of some of the microcontroller-related design issues which arise and learning opportunities offered.4.1 MathematicalModelLumped-element thermal systems are described in almost any introductory linear control systems text, and just this sort of model is applicable to the slide dryer problem. Figure 4 shows a second-order lumped-element thermal model of the slide dryer. The state variables are the temperatures Ta of the air in the box and Tb of the box itself. The inputs to the system are the power output q(t) of the heater and the ambient temperature T¥. ma and mb are the masses of the air and the box, respectively, and Ca and Cb their specific heats. μ1 and μ2 are heat transfer coefficients from the air to the box and from the box to the external world, respectively.It’s not hard to show that the (linearized) state equationscorresponding to Figure 4 areTaking Laplace transforms of (1) and (2) and solving for Ta(s), which is the output of interest, gives the following open-loop model of the thermal system:where K is a constant and D(s) is a second-order polynomial.K, tz, and the coefficients ofD(s) are functions of the variousparameters appearing in (1) and (2).Of course the various parameters in (1) and (2) are completely unknown, but it’s not hard to show that, regardless of their values, D(s) has two real zeros. Therefore the main transfer function of interest (which isthe one from Q(s), since we’ll assume constant ambient temperature) can be writtenMoreover, it’s not too hard to show that 1=tp1 <1=tz <1=tp2, i.e., that the zero lies between the two poles. Both of these are excellent exercises for the student, and the result is the openloop pole-zero diagram of Figure 5.Obtaining a complete thermal model, then, is reduced to identifying the constant K and the three unknown time constants in (3). Four unknown parameters is quite a few, but simple experiments show that 1=tp1 _ 1=tz;1=tp2 so that tz;tp2 _ 0 are good approximations. Thus the open-loop system is essentially first-order and can therefore be written(where the subscript p1 has been dropped).Simple open-loop step response experiments show that,for a wide range of initial temperatures and heat inputs, K _0:14 _=W and t _ 295 s.14.2 Control System DesignUsing the first-order model of (4) for the open-loop transfer function Gaq(s) and assuming for the moment that linear control of the heater power output q(t) is possible, the block diagram of Figure 6 represents the closed-loop system. Td(s) is the desired, or set-point, temperature,C(s) is the compensator transfer function, and Q(s) is the heater output in watts.Given this simple situation, introductory linear control design tools such as the root locus method can be used to arrive at a C(s) which meets the step response requirements on rise time, steady-state error, and overshoot specified in Table 1. The upshot, of course, is that a proportional controller with sufficient gain can meet all specifications. Overshoot is impossible, and increasing gains decreases both steady-state error and rise time.Unfortunately, sufficient gain to meet the specifications may require larger heat outputs than the heater is capable of producing. This was indeed the case for this system, and the result is that the rise time specification cannot be met. It is quite revealing to the student how useful such an oversimplified model, carefully arrived at, can be in determining overall performance limitations.4.3 Simulation ModelGross performance and its limitations can be determined using the simplified model of Figure 6, but there are a number of other aspects of the closed-loop system whose effects on performance are not so simply modeled. Chief among these are·quantization error in analog-to-digital conversion of the measured temperature and· the use of PWM to control the heater.Both of these are nonlinear and time-varying effects, and the only practical way to study them is through simulation (or experiment, of course).Figure 7 shows a SimulinkTM block diagram of the closed-loop system which incorporates these effects. A/D converter quantization and saturation are modeled using standard Simulink quantizer and saturation blocks. Modeling PWM is more complicated and requires a customS-function to represent it.This simulation model has proven particularly useful in gauging the effects of varying thebasic PWM parameters and hence selecting them appropriately. (I.e., the longer the period, the larger the temperature error PWM introduces. On the other hand, a long period is desirable to avoid excessive relay “chatter,” among other things.) PWM is often difficult for students to grasp, and the simulation model allows an exploration of its operation and effects which is quite revealing.4.4 The MicrocontrollerSimple closed-loop control, keypad reading, and display control are some of the classic applications of microcontrollers, and this project incorporates all three. It is therefore an excellent all-around exercise in microcontroller applications. In addition, because the project isto produce an actual packaged prototype, it won’t do to use a simple evaluation board with theI/O pins jumpered to the target system. Instead, it’s necessary to develop a complete embedded application. This entails the choice of an appropriate part from the broad range offered in a typical microcontroller family and learning to use a fairly sophisticated development environment. Finally, a custom printed-circuit board for the microcontroller and peripherals must be designed and fabricated.Microcontroller Selection. In view of existing local expertise, the Motorola line of microcontrollers was chosen for this project. Still, this does not narrow the choice down much. A fairly disciplined study of system requirements is necessary to specify which microcontroller, out of scores of variants, is required for the job. This is difficult for students, as they generally lack the experience and intuition needed as well as the perseverance to wade through manufacturers’ selection guides.Part of the problem is in choosing methods for interfacing the various peripherals (e.g., what kind of display driver should be used?). A study of relevant Motorola application notes [2, 3, 4] proved very helpful in understandingwhat basic approaches are available, and what microcontroller/peripheral combinations should be considered.The MC68HC705B16 was finally chosen on the basis of its availableA/D inputs and PWMoutputs as well as 24 digital I/O lines. In retrospect this is probably overkill, as only oneA/D channel, one PWM channel, and 11 I/O pins are actually required (see Figure 3). The decision was made to err on the safe side because a complete development system specific to the chosen part was necessary, and the project budget did not permit a second such system to be purchased should the firstprove inadequate.Microcontroller Application Development. Breadboarding of the peripheral hardware, development of microcontroller software, and final debugging and testing of a customprinted-circuit board for the microcontroller and peripherals all require a development environment of some kind. The choice of a development environment, like that of themicrocontroller itself, can be bewildering and requires some faculty expertise. Motorola makes three grades of development environment ranging from simple evaluation boards (at around $100) to full-blown real-time in-circuit emulators (at more like $7500). The middle option was chosen for this project: the MMEVS, which consists of _ a platform board (which supports all 6805-family parts), _ an emulator module (specific to B-series parts), and _ a cable and target head adapter (package-specific). Overall, the system costs about $900 and provides, with some limitations, in-circuit emulation capability. It also comes with the simple but sufficient software development environment RAPID [5].Students find learning to use this type of system challenging, but the experience they gain in real-world microcontroller application development greatly exceeds the typical first-course experience using simple evaluation boards.Printed-Circuit Board. The layout of a simple (though definitely not trivial) printed-circuit board is another practical learning opportunity presented by this project. The final board layout, with package outlines, is shown (at 50% of actual size) in Figure 8. The relative simplicity of the circuit makes manual placement and routing practical—in fact, it likely gives better results than automatic in an application like this—and the student is therefore exposed to fundamental issues of printed-circuit layout and basic design rules. The layout software used was the very nice package pcb,2 and the board was fabricated in-house with the aid of our staff electronics technician.5 ConclusionThe aim of this paper has been to describe an interdisciplinary, undergraduate engineering design project: a microcontroller- based temperature control system with digital set-point entry and set-point/actual temperature display. A particular design of such a system has been described, and a number of design issues which arise—from a variety of engineering disciplines—have been discussed. Resolution of these issues generally requires knowledge beyond that acquired in introductory courses, but realistically accessible to advance undergraduate students, especiallywith the advice and supervision of faculty.Desirable features of the problem, from a pedagogical viewpoint, include the use of a microcontroller with simple peripherals, the opportunity to usefully apply introductorylevel modeling of physical systems and design of closed-loop controls, and the need for relatively simple experimentation (for model validation) and simulation (for detailed performance prediction). Also desirable are some of the technologyrelated aspects of the problem including practical use of resistive heaters and temperature sensors (requiring knowledge of PWM and calibration techniques, respectively), microcontroller selection and use of development systems, and printedcircuit design.AcknowledgementsThe author would like to acknowledge the hard work, dedication, and ability shown by the students involved in this project: Mark Langsdorf, Matt Rall, PamRinehart, and David Schuchmann. It is their project, and credit for its success belongs to them.References[1] M. Langsdorf, M. Rall, D. Schuchmann, and P. Rinehart,“Temperature control of a microscope slide dryer,” in1997 National Conference on Undergraduate Research,(Austin, TX), April 1997. Poster presentation.[2] Motorola, Inc., Phoenix, AZ, Temperature Measurementand Display Using the MC68HC05B4 and the MC14489,1990. Motorola SemiconductorApplicationNote AN431.[3] Motorola, Inc., Phoenix, AZ, HC05 MCU LED DriveTechniques Using the MC68HC705J1A, 1995. MotorolaSemiconductor Application Note AN1238.[4] Motorola, Inc., Phoenix, AZ, HC05MCU Keypad DecodingTechniques Using the MC68HC705J1A, 1995. MotorolaSemiconductor Application Note AN1239.[5] Motorola, Inc., Phoenix, AZ, RAPID Integrated DevelopmentEnvironment User’s Manual, 1993. (RAPID wasdeveloped by P & E Microcomputer Systems, Inc.).单片机温度控制：一个跨学科的本科生工程设计项目JamesS.McDonald工程科学系三一大学德克萨斯州圣安东尼奥市78212摘要本文所描述的是作者领导由四个三一大学高年级学生组成的团队进行的一个跨学科工程项目的设计。

BI YE SHE JI( 届)基于单片机的智能风扇控制器设计(英文) An Intelligent Controller for Fan Based on Single Chip Microcomputer所在学院电子信息学院专业班级电子信息工程学生姓名学号指导教师职称完成日期年月日摘要提出了以C8051F005为控制器，利用可控硅调速的智能风扇控制器的设计方案。

该系统可以实现对风扇的风速调节和风类型转换的控制，可以设定风扇的工作模式。

单片机通过控制可控硅导通角，来实现风扇的无级调速，并利用单片机内部的温度传感器采集环境温度，对风扇进行智能控制。

详细分析了系统的五大模块：单片机模块、过零检测模块、可控硅触发模块、键盘遥控模块和LCD显示模块，详细的论述了风扇控制器对风扇的控制过程。

过零检测模块可以检测出交流电压的过零点，作为单片机发出触发脉冲的参考点；键盘和遥控模块可以对控制器进行设定，用于选择风扇的工作方式；LCD显示模块用于显示风扇风速，风类型，当前工作模式和环境温度等信息。

关键词：风扇；C8051F005；可控硅AbstractFirst discusses the development and the application of fan.Put forward the design scheme that an intelligent fan controller based on C8051F005 single-chip use Thyristor to control its spend. The program choice the C8051F005 single-chip to control thyristor’s conduction angle , then to realize the stepless speed regulation of fan. And it can use the single-chip internal temperature sensor to collect the environmental temperature, to realize Auto-control of ing internal timer of SCM to control thyristor’s conduction by sending out pulse when time is over.The length of timer relate with thyristor’s conduction angle. A detailed analysis of the five modules of the system that includes MCU module, zero crossing detection module, Keys and remote control module，LCD module and a thyristor trigger module. A detailed discussion on fan control about fan controller also will be given. The system can control the speed and wind’s ty pe of fan , you can set the working mode of fan. The zero examination module can detect sinusoidal voltage of zero, as a point of reference to send out pulse by single chip microcomputer. you can set the working of fan by keys and remote control module. LCD display module used to show wind speed, the wind type, the current working mode and the environment temperature and other information.Key Words:fan; C8051F005 ; thyristor;目录第一章引言 (1)1.1 电风扇的应用和发展 (1)1.2 本文主要内容及课题要求 (2)第二章风扇控制器设计方案 (3)2.1 风扇转速控制原理 (3)2.2 总体设计方案 (4)2.3 单片机模块 (5)2.4 过零检测模块 (5)2.5 可控硅触发模块 (5)2.6 LCD显示模块 (5)2.7 键盘模块 (5)第三章硬件设计 (7)3.1 电机调速电路设计 (7)3.1.1 过零检测电路 (7)3.1.2可控硅触发电路 (8)3.2 人机接口电路设计 (9)3.1.1显示部分设计 (9)3.1.2键盘部分设计 (9)3.3 C8051F005单片机电路 (10)3.3.1C8051F005基本配置 (10)3.3.2时钟电路 (11)第四章软件设计 (13)4.1 软件设计的要点 (13)4.2主程序流程设计 (13)4.3风扇工作模式设计 (13)4.3.1自动控制程序设计................................................................ 错误!未定义书签。

本科毕业设计（外文翻译）题目基于单片机的自动调温风扇系统设计姓名丁蒙恩专业电子科学与技术学号 3指导教师张军郑州科技学院电气工程学院二○一三年五月外文翻译原文：System design based on single chip microcomputerautomatic temperature adjustment fan Temperature control fan in the modern social production and People's Daily life have a wide range of applications, such as industrial production and large mechanical cooling fan in the system, now widely used on laptops smart CPU fan, etc. Design based on single chip microcomputer temperature control fan system, this paper adopts the single chip microcomputer as controller, using temperature sensor DS18B20 as temperature gathering element, and according to the collected temperature through a darlington reverse drive driven ULN2803 fan motor. According to the detected temperature was compared with the system set the temperature of the implementation of the fan motor start and stop automatically, and can root temperature changes automatically changes the speed of the fan motor, at the same time with eight digital tube LED display temperature and setting temperature is detected.I. IntroductionWith the wide application of microcontroller in various fields, many of the temperature control system using single chip microcomputer as control also arises at the historic moment, such as system based on single chip microcomputer temperature control fan. It makes the fan according to the change of environmental temperature automatic start-stop, the fan speed changes with the change of environmental temperature, fan intelligent control is realized. Its design for the modern society has brought many convenient people's life and production, to improve people's quality of life, the production efficiency but also can save the energy for the fan operation.This paper was designed by the ATMEL company 8052 series single-chip computer AT89C52 as the controller, the temperature sensor by DALLAS company DS18B20 as temperature gathering element, and through a darlington reverse drive the rotation of the fan motor driven ULN2803. At the same time, make the system detected ambient temperature as well as the system default temperature dynamic display on LED digital tube. According to the system detects the ambient temperature and the comparison of the preset temperature, realize automatic start-stop of the fan motor and speed automatic adjustment.II. System Overall Structure DesignIs the overall train of thought of this design: using temperature sensor DS18B20 testing environment temperature and directly output digital signals to single chip microcomputer AT89C52, on the LED digital tube display the current environment temperature and the preset temperature. The preset temperature can form as an integer, detects the current environment temperature can be accurate to one decimal place. At the same time adopts the PWM pulse width modulation method to change the dc fan motor speed. And through the two buttons to change the default value, a preset temperature, another reduce the preset temperature.III. the unit module's hardware designSystem mainly includes device DS18B20 temperature sensor, and AT89C52 single-chip microcomputer and five LED digital tube, fan Yin reverse drive dc motor, darlington ULN2803. Auxiliary components include resistors capacitors, crystal vibration, power supplies, buttons, dial the code switch, etc.part of the system devicessingle line digital temperature sensorDS18B20 digital temperature sensor, is using the American DALLAS semiconductor company production of DS18B20 digital temperature sensor networking chip packaging, it has the miniaturization, low power consumption, high performance, strong anti-interference ability, easy to match advantage such asmicroprocessors, temperature can be directly converted to a serial digital signal processor for processing.The main characteristic of DS18B20: measuring results directly in the form of a digital signal output, with "1-wire bus" means serial port sent to the CPU, can send CRC check code at the same time, with strong ability of anti-interference error correction; Temperature measurement range between - 55 ℃ ~ + 125 ℃, at - 10 ℃ ~ + 85 ℃ accuracy of plus or minus ℃; Detects the temperature resolution for 9 ~ 12, corresponding distinguished temperature ℃, respectively, ℃, ℃and ℃, which can realize high precision temperature measurement; The uniqueness of the single wire interface, it makes only a port when it is connected with the microprocessor line can be realized with the two-way communication of the microprocessor; Support more network function, that is, multiple DS18B20 can be parallel on only three lines, achieve network function of multipoint temperature measurement; Wide working voltage range, the range from V to V.DS18B20 internal structure mainly has four parts: a 64 - bit ROM, the temperature of the temperature sensors, nonvolatile alarm trigger TH and TL, the configuration register. The pin has three, the DQ for digital signal, GND for power supply, VDD power input end.to the AT89C52 single chip microcomputerIs one of the 51 series single chip microcomputer AT89C52 model, it is produced by the ATMEL company a low voltage, high-performance 8-bit microcontroller, on chip device adopts nonvolatile of ATMEL company, high-density storage technology production, compatible with standard of MCS - 51 command system, at the same time with general 8-bit CPU and 8 k bytes can be repeatedly wipe read-only program memory RAM, ROM and 256 gigabytes of data memory in many, many more complex control system is AT89C52 single chip microcomputer has been widely used. AT89C52 40 pin.part of the circuit designis reset and crystal oscillator circuitIn microcomputer application system, in addition to the microcontroller itself needs to be reset, external expansion I/O interface circuit also need to be reset, so you need a system, including electricity and button to reset synchronous reset circuit. Single-chip microcomputer XTAL1 and XTAL2 for external quartz crystal and fine-tuning capacitor, which used to connect the MCU chip OSC time feedback loop. This switch is reset and crystal oscillator circuit in the design of as shown in the figure below, when press the button switch S1, system reset at a time. For 20 pf capacitor C1, C2, C3 is 10 uf, the 10 k resistor R2, and R3, crystals of MHz. acquisition circuitDS18B20 digital temperature sensor by counting its internal clock cycles to effect, achieve the function of peculiar temperature measurement. Low temperature coefficient of the clock oscillator output signal generated by high temperature coefficient of oscillator's door was counting cycles, and counter with advance and 55 ℃ corresponding weights of a base. If counter count to zero, the high temperature coefficient of oscillation period is not over, said the measured temperature value is higher than 55 ℃, were prepared in the register - 55 ℃ temperature increases, the value 1 ℃, and the process repeats itself, until the end of the high temperature coefficient of oscillation cycle. Temperature register at this time of the measured temperature value, value is the value stored in memory in the form of a 16-bit binary, sent by the host memory read command to read the temperature value, when read in low, high,. Because of the influence of the temperature oscillator parabolic characteristics, which use the slope accumulator to compensate.motor drive and control circuitOf MCU I/O mouth in the design of the PWM output pulse, through a darlington reverse drive driven ULN2803 12 v brushless dc fan motor and fan motor speed regulation.Keyboard set temperature control, through the software corresponding input to the MCU control instruction, by single-chip microcomputer through port output and speed corresponding PWM pulse, after driven ULN2803 fan motor control circuit, realize automatic control of motor speed and the rev. Stop. Whenenvironment temperature, the dc motor speed will be in accordance with the corresponding set level increased; When environment temperature drop, the motor speed will accordingly decrease; When environment temperature is below the set temperature, the motor stop running, and the environment temperature is higher than the preset temperature, the motor is restarted.IV .The software designSoftware design includes application Settings, programming and software simulation. Program design part mainly includes the main program, DS18B20 initialization function, DS18B20 temperature conversion function, temperature reading functions, the keyboard scanning function, digital tube display, temperature processing function and control function of the motor. DS18B20 initialization function of DS18B20 initialization; DS18B20 temperature conversion function complete real-time collection of temperature; Temperature reading function complete host on the temperature sensor data reading and data conversion, keyboard scanning function is set according to the need to complete initial value and subtract; Temperature processing function to analyze the collected temperature, provide the conditions for motor speed changes; Fan motor control function was completed according to the temperature of the numerical control of motor speed and rev. Stop.With Proteus simulation Proteus has four function modules: the first smart principle diagram design, complete the circuit simulation function, unique collaborative simulation microcontroller and practical platform for the PCB design. Its internal components library contains rich components to support intelligent bus structure and attachment function; Support mainstream CPU (such as ARM, 8051/52, AVR) and its general real-time simulation model of the peripheral, etc., brings great convenience for the development and application of single-chip microcomputer, etc. Start the Proteus software and establish a project, and then according to the principle diagram of the corresponding original, again according to the request to change the original properties and connect various components according to the principlediagram. In the schematic drawing good connection and then loads the compiled program to them. According to the simulation system to realize the function step by step.CONCLUSIONthis system can be used in simple daily fan intelligent control, bring convenience for the life; In industrial production, can change the different input signal, the implementation of different control motor speed signal input, and then realize the production automation, such as in power system can achieve different according to different load voltage signal, again by the generator voltage signal to adjust different rotating speed, and then adjust the power, realize the automation of electric power system. To sum up, the system design and research has the important status in social production and life.译文：基于单片机的自动调温风扇系统设计温控风扇在现代社会中的生产和人们的日常生活中都有普遍的应用，如工业生产中大型机械散热系统中的风扇、此刻笔记本电脑上的普遍应用的智能CPU 风扇等。

目录第1节引言 (3)1.1 智能电风扇控制系统概述 (3)1.2 本设计任务和主要内容 (3)第2节系统主要硬件电路设计 (5)2.1 总体硬件设计 (5)2.2 数字温度传感器模块设计 (5)2.2.1 温度传感器模块的组成 (5)2.2.2 DS18B20的温度处理方法 (6)2.3 电机调速与控制模块设计 (7)2.3.1 电机调速原理 (7)2.3.2 电机控制模块硬件设计 (8)2.4 温度显示与控制模块设计 (9)第3节系统软件设计 (10)3.1 数字温度传感器模块程序设计 (10)3.2 电机调速与控制模块程序流程 (15)3.2.1 程序设计原理 (15)3.2.2 主要程序 (16)第4节结束语 (19)参考文献 (20)基于单片机的智能电风扇控制系统第1节引言电风扇曾一度被认为是空调产品冲击下的淘汰品，其实并非如此，市场人士称，家用电风扇并没有随着空调的普及而淡出市场，近两年反而出现了市场销售复苏的态势。

其主要原因：一是风扇和空调的降温效果不同——空调有强大的制冷功能，可以快速有效地降低环境温度，但电风扇的风更温和，更加适合老人儿童和体质较弱的人使用；二是电风扇有价格优势，价格低廉而且相对省电，安装和使用都非常简单。

尽管电风扇有其市场优势，但传统电风扇还是有许多地方应当进行改良的，最突出的缺点是它不能根据温度的变化适时调节风力大小，对于夜间温差大的地区，人们在夏夜使用电风扇时可能遇到这样的问题：当凌晨降温的时候电风扇依然在工作，可是人们因为熟睡而无法察觉，既浪费电资源又容易引起感冒，传统的机械定时器虽然能够控制电风扇在工作一定后关闭，但定时范围有限，且无法对温度变化灵活处理。

鉴于以上方面的考虑，我们需要设计一种智能电风扇控制系统来解决这些问题。

1.1 智能电风扇控制系统概述传统电风扇是220V交流电供电，电机转速分为几个档位，通过人为调整电机转速达到改变风力大小的目的，亦即，每次风力改变，必然有人参与操作，这样势必带来诸多不便。

摘要本文介绍一种基于单片机温控风扇的控制系统设计方案。

巧妙地利用单片机技术，可控硅技术，温度传感器技术。

硬件系统采用AT89C51作为微处理器，利用DS18B20对室内温度的探测并适时显示当前温度值，通过控制可控硅的导通，从而实现对电风扇进行温度调速控制。

软件系统则采用模块设计即主程序，键盘控制程序，温度显示程序，电机调速程序。

文中给出AT89C51为核心的电路设计主体软件设计，着重讨论温控相关程序的设计并给出流程图和相关程序。

关键词：AT89C51;DS18B20;仿真，电机调速，温度显示AbstractThis paper introduces a control based on single-chip microcomputer control system design scheme of the fan. Ingenious of single chip microcomputer, thyristor technology , the temperature sensor technology.Hardware system AT89C51 as microprocessors , use of indoor temperature detection DS18B20 and display the current controlled temperature, through the control of conduction, so as to realize the fan speed control of temperature. Software system is a modular design which main program, keyboard control procedures, temperature display program, motor speed program. Given the circuit design as the core of AT89C51 main software design, emphatically discusses the design and temperature control procedures are flowchart and relevant procedure.Keywords: AT89C51, DS18B20, Simulation, motor speed, temperature display目录第1章引言 (3)1.1 课题的设计要求 (3)1.2 课题的设计目的和意义 (3)第2章系统主要硬件电路设计 (4)2.1 总体硬件设计 (4)2.1.1 AT89C51介绍及说明 (4)2.1.2 AT89C51主要特性及引脚说明 (5)2.2 数字温度传感器模块设计 (8)2.2.1 DS18B20介绍 (8)2.2.2 DS18B20的功能及使用说明 (9)2.2.3 DS18B20寄存器的存储器及格式 (10)2.2.4 DS18B20使用注意事项 (11)2.3 键盘输入模块 (11)2.3.1 键盘的选择与原理 (11)2.3.2 键盘电路 (12)2.4 温度显示与控制模块 (13)2.4.1 LED显示灯介绍 (13)2.5 电机调速与控制模块设计 (14)2.5.1 电机调速原理 (15)2.5.2 电机控制模块硬件设计 (16)第3章软件设计与说明（包括流程图） (18)3.1 系统方案设计 (18)3.2 主要程序流程图 (18)3.2.1 主程序流程图 (18)3.2.2 数字温度传感器模块程序流程图 (19)3.2.3 显示程序流程图 (21)3.2.4 电动机程序设计原理以及流程图 (21)第4章调试步骤、结果、使用说明 (23)第5章设计总结 (24)附录A 系统原理图 (25)附录B 程序清单 (25)参考文献 (34)第1章引言1.1 课题的设计要求本课题要求以单片机为核心设计一个智能风扇控制器，具备倒数计时、时间修改、实时显示温度、预设关机温度、预设报警温度等功能。

1. 基于51单片机的智能温控风扇毕业设计外文文献在进行智能温控风扇毕业设计时，外文文献的引用是非常重要的。

通过外文文献的查阅和引用，可以帮助毕业设计的学生更好地了解相关领域的最新进展和研究成果，为毕业设计的深度和广度提供更多的支持和依据。

2. 智能温控风扇设计的核心技术在外文文献中，对于智能温控风扇设计的核心技术有着详细的介绍和探讨。

通过了解外文文献中的相关内容，可以更好地掌握基于51单片机的智能温控风扇设计的关键技术和方法，为毕业设计提供更加系统和完整的技术支持。

3. 智能温控风扇设计的相关算法外文文献中通常会介绍和分析智能温控风扇设计中所涉及的相关算法，如温度控制算法、风速调节算法等。

通过对外文文献中相关算法的学习和借鉴，可以为毕业设计的算法设计提供宝贵的经验和参考，使得智能温控风扇的设计更加科学和实用。

4. 智能温控风扇设计的前沿研究外文文献还会介绍关于智能温控风扇设计的前沿研究成果和最新进展，如基于人工智能的智能温控风扇设计、智能温控风扇与物联网的融合等。

通过对外文文献中前沿研究的了解，可以为毕业设计注入更多的创新元素和未来发展方向，使得毕业设计更具有前瞻性和科技含量。

5. 个人观点和总结在进行智能温控风扇毕业设计时，充分利用外文文献的信息资源是非常重要的。

通过对外文文献的深入研读和理解，可以为毕业设计提供更加全面、深刻和灵活的支持，使得毕业设计的质量和水平得到有效提升。

基于51单片机的智能温控风扇毕业设计外文文献是毕业设计过程中不可或缺的重要组成部分。

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Design of the Temperature Control System Based onAT89C51ABSTRACTThe principle and functions of the temperature control system based on micro controller AT89C51 are studied, and the temperature measurement unit consists of the 1-Wire bus digital temperature sensor DS18B20. The system can be expected to detect the preset temperature, display time and save monitoring data. An alarm will be given by system if the temperature exceeds the upper and lower limit value of the temperature which can be set discretionarily and then automatic control is achieved, thus the temperature is achieved monitoring intelligently within a certain range. Basing on principle of the system, it is easy to make a variety of other non-linear control systems so long as the software design is reasonably changed. The system has been proved to be accurate, reliable and satisfied through field practice.KEYWORDS: AT89C51; micro controller; DS18B20; temperature 1 INTRODUCTIONTemperature is a very important parameter in human life. In the modern society, temperature control (TC) is not only used in industrial production, but also widely used in other fields. With the improvement of the life quality, we can find the TC appliance in hotels, factories and home as well. And the trend that TC will better serve the whole society, so it is of great significance to measure and control the temperature. Based on the AT89C51 and temperature sensor DS18B20, this system controls the condition temperature intelligently. The temperature can be set discretionarily within a certain range. The system can show the time on LCD, and save monitoring data; andautomatically control the temperature when the condition temperature exceeds the upper and lower limit value. By doing so it is to keep the temperature unchanged. The system is of high anti-jamming, high control precision and flexible design; it also fits the rugged environment. It is mainly used in people's life to improve the quality of the work and life. It is also versatile, so that it can be convenient to extend the use of the system. So the design is of profound importance. The general design, hardware design and software design of the system are covered.1.1 IntroductionThe 8-bit AT89C51 CHMOS microcontrollers are designed to handle high-speed calculations and fast input/output operations. MCS 51 microcontrollers are typically used for high-speed event control systems. Commercial applications include modems, motor-control systems, printers, photocopiers, air conditioner control systems, disk drives, and medical instruments. The automotive industry use MCS 51 microcontrollers in engine-control systems, airbags, suspension systems, and antilock braking systems (ABS). The AT89C51 is especially well suited to applications that benefit from its processing speed and enhanced on-chip peripheral functions set, such as automotive power-train control, vehicle dynamic suspension, antilock braking, and stability control applications. Because of these critical applications, the market requires a reliable cost-effective controller with a low interrupt latency response, ability to service the high number of time and event driven integrated peripherals needed in real time applications, and a CPU with above average processing power in a single package. The financial and legal risk of having devices that operate unpredictably is very high. Once in the market, particularly in mission critical applications such as an autopilot or anti-lock braking system, mistakesare financially prohibitive. Redesign costs can run as high as a $500K, much more if the fix means 2 back annotating it across a product family that share the same core and/or peripheral design flaw. In addition, field replacements of components is extremely expensive, as the devices are typically sealed in modules with a total value several times that of the component. To mitigate these problems, it is essential that comprehensive testing of the controllers be carried out at both the component level and system level under worst case environmental and voltage conditions. This complete and thorough validation necessitates not only a well-defined process but also a proper environment and tools to facilitate and execute the mission successfully. Intel Chandler Platform Engineering group provides post silicon system validation (SV) of various micro-controllers and processors. The system validation process can be broken into three major parts. The type of the device and its application requirements determine which types of testing are performed on the device.1.2 The AT89C51 provides the following standard features4Kbytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bittimer/counters, a five vector two-level interrupt architecture, a full duple ser-ial port, on-chip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt sys -tem to continue functioning. The Power-down Mode saves the RAM contents but freezes the oscil–lator disabling all other chip functions until the next hardware reset.1.3Pin DescriptionVCC Supply voltage.GND Ground.Port 0：Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high impedance inputs. Port 0 may also be configured to be the multiplexed low order address/data bus during accesses to external program and data memory. In this mode P0 has internal pull ups. Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during program verification. External pull ups are required during program verification.Port 1：Port 1 is an 8-bit bi-directional I/O port with internal pull ups. The Port 1 output buffers can sink/so -urce four TTL inputs. When 1s are written to Port 1 pins they are pulled high by the internal pull ups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pullups. Port 1 also receives the low-order address bytes during Flash programming and verification.Port 2：Port 2 is an 8-bit bi-directional I/O port with internal pull ups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins they are pulled high by the internal pull ups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pull ups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pull ups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX@DPTR). In this application,it uses strong internal pull-ups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-order address bits and some control signals durin Flash programming and verification.Port 3：Port 3 is an 8-bit bi-directional I/O port with internal pull ups. The Port 3 output buffers can sink/sou -rce four TTL inputs. When 1s are written to Port 3 pins they are pulled high by the internal pull ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pull ups.Port 3 also serves the functions of various special features of the AT89C51 as listed below:RST：Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device.ALE/PROG：Address Latch Enable output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped duri-ng each access to external Data Memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.PSEN：Program Store Enable is the read strobe to external program memory. When theAT89C51 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skippedduring each access to external data memory.EA/VPP：External Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to VCC for internal program executions. This pin alsreceives the 12-volt programming enable voltage (VPP) during Flash programming, for parts that require 12-volt VPP.XTAL1：Input to the inverting oscillator amplifier and input to the internal clock operating circuit.XTAL2 ：Output from the inverting oscillator amplifier. Oscillator CharacteristicsXTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier which can be configured for use as an on-chip oscillator, as shown in Figure 1. Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure 2.There are no requirements on the duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications must be observed. Idle Mode In idle mode, the CPU puts itself to sleep while all the on chip peripherals remain active. The mode is invoked by software. The content of the on-chip RAM and all the special functions registers remain unchanged during this mode. The idle mode can be terminated by any enabled interrupt or by a hardware reset. It should be noted that when idle is terminated by a hard ware reset, the device normally resumes program execution, from where it left off, up to two machine cycles before the internal reset algorithm takes control. On-chip hardware inhibits accessto internal RAM in this event, but access to the port pins is not inhibited. To eliminate the possibility of an unexpected write to a port pin when Idle is terminated by reset, the instruction following the one that invokes Idle should not be one that writes to a port pin or to external memory.Power-down ModeIn the power-down mode, the oscillator is stopped, and the instruction that invokes power-down is the last instruction executed. The on-chip RAM and Special Function Registers retain their values until the power-down mode is terminated. The only exit from power-down is a hardware reset. Reset redefines the SFRS but does not change the on-chip RAM. The reset should not be activated before VCC is restored to its normal operating level and must be held active long enough to allow the oscillator to restart and stabilize. The AT89C51 code memory array is programmed byte-by byte in either programming mode. To program any nonblank byte in the on-chip Flash Memory, the entire memory must be erased using the Chip Erase Mode.2 Programming AlgorithmBefore programming the AT89C51, the address, data and control signals should be set up according to the Flash programming mode table and Figure 3 and Figure 4. To program the AT89C51, take the following steps.1. Input the desired memory location on the address lines.2. Input the appropriate data byte on the data lines. 3. Activate the correct combination of control signals. 4. Raise EA/VPP to 12V for the high-voltage programming mode. 5. Pulse ALE/PROG once to program a byte in the Flash array or the lock bits. The byte-write cycle is self-timed and typically takes no more than 1.5 ms. Repeat steps 1 through 5, changing the address and data for the entire array or until the end of the object reached. Data Polling: The AT89C51features Data Polling to indicate the end of a write cycle. During a write cycle, an attempted read of the last byte written will result in the complement of the written datum on PO.7. Once the write cycle has been completed, true data are valid on all outputs, and the next cycle may begin. Data Polling may begin any time after a write cycle has been initiated.2.1Ready/Busy:The progress of byte programming can also be monitored by the RDY/BSY output signal. P3.4 is pulled low after ALE goes high during programming to indicate BUSY. P3.4 is pulled high again when programming is done to indicate READY.Program Verify:If lock bits LB1 and LB2 have not been programmed, the programmed code data can be read back via the address and data lines for verification. The lock bits cannot be verified directly. Verification of the lock bits is achieved by observing that their features are enabled.2.2 Chip Erase:The entire Flash array is erased electrically by using the proper combination of control signals and by holding ALE/PROG low for 10 ms. The code array is written with all “1”s. The chip erase operation must be executed before the code memory can be re-programmed.2.3 Reading the Signature Bytes:The signature bytes are read by the same procedure as a normal verification of locations 030H, 031H, and 032H, except that P3.6 and P3.7 must be pulled to a logic low. The values returned areas follows.(030H) = 1EH indicates manufactured by Atmel(031H) = 51H indicates 89C51(032H) = FFH indicates 12V programming(032H) = 05H indicates 5V programming2.4 Programming InterfaceEvery code byte in the Flash array can be written and the entire array can be erased by using the appropriate combination of control signals. The write operation cycle is self timed and once initiated, will automatically time itself to completion. A microcomputer interface converts information between two forms. Outside the microcomputer the information handled by an electronic system exists as a physical signal, but within the program, it is represented numerically. The function of any interface can be broken down into a number of operations which modify the data in some way, so that the process of conversion between the external and internal forms is carried out in a number of steps. An analog-to-digital converter(ADC) is used to convert a continuously variable signal to a corresponding digital form which can take any one of a fixed number of possible binary values. If the output of the transducer does not vary continuously, no ADC is necessary. In this case the signal conditioning section must convert the incoming signal to a form which can be connected directly to the next part of the interface, the input/output section of the microcomputer itself. Output interfaces take a similar form, the obvious difference being that here the flow of information is in the opposite direction; it is passed from the program to the outside world. In this case the program may call an output subroutine which supervises the operation of the interface and performs the scaling numbers which may be needed for digital-to-analog converter(DAC). This subroutine passes information in turn to an output device which produces a corresponding electrical signal, which could be converted into analog form using a DAC. Finally the signal is conditioned(usually amplified) to a form suitable for operating an actuator.The signals used within microcomputer circuits are almost always too small to be connected directly to the outside world” and some kind of interface must be used to translate them to a more appropriate form. The design of section of interface circuits is one of the most important tasks facing the engineer wishing to apply microcomputers. We have seen that in microcomputers information is represented as discrete patterns of bits; this digital form is most useful when the microcomputer is to be connected to equipment which can only be switched on or off, where each bit might represent the state of a switch or actuator. To solve real-world problems, a microcontroller must have more than just a CPU, a program, and a data memory. In addition, it must contain hardware allowing the CPU to access information from the outside world. Once the CPU gathers information and processes the data, it must also be able to effect change on some portion of the outside world. These hardware devices, called peripherals, are the CPU’s window to the outside.The most basic form of peripheral available on microcontrollers is the general purpose I70 port. Each of the I/O pins can be used as either an input or an output. The function of each pin is determined by setting or clearing corresponding bits in a corresponding data direction register during the initialization stage of a program. Each output pin may be driven to either a logic one or a logic zero by using CPU instructions to pin may be viewed (or read.) by the CPU using program instructions. Some type of serial unit is included on microcontrollers to allow the CPU to communicate bit-serially with external devices. Using a bit serial format instead of bit-parallel format requires fewer I/O pins to perform the communication function, which makes it less expensive, but slower. Serial transmissions are performed either synchronously orasynchronously.3 SYSTEM GENERAL DESIGNThe hardware block diagram of the TC is shown in Fig.1. The system hardware includes the micro controller, temperature detection circuit, keyboard control circuit, clock circuit, Display, alarm, drive circuit and external RAM. Based on the AT89C51, the DS18B20 will transfer the temperature signal detected to digital signal. And the signal is sent to the micro controller for processing. At last the temperature value is showed on the LCD 12232F. These steps are used to achieve the temperature detection. Using the keyboard interface chip HD7279 to set the temperature value, using the micro controller to keep a certain temperature, and using the LCD to show the preset value for controlling the temperature. In addition, the clock chip DS1302 is used to show time and the external RAM 6264 is used to save the monitoring data. An alarm will be given by buzzer in time if the temperature exceeds the upper and lower limit value of the temperature.3.1 HARDWARE DESIGNA. Micro controllerThe AT89C51 is a low-power, high-performance CMOS 8-bit micro controller with 4K bytes of in-system programmable Flash memory. The device is manufactured using At mel’s high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pin out. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the At mel AT89C51 is a powerful micro controller which provides a highly-flexible and cost-effective solution to many embedded controlapplications. Minimum system of the micro controller is shown in Fig. 2. In order to save monitoring data, the 6264 is used as an external RAM. It is a static RAM chip, low-power with 8K bytes memory.B. Temperature Detection CircuitThe temperature sensor is the key part in the system. The Dallas DS18B20 is used, which supports the 1-Wire bus interface, and the ON-BOARD Patented is used internally. All the sensor parts and the converting circuit are integrated in integrated circuit like a transistor [1]. Its measure range is -55℃~125 ℃, and the precision between -10℃~85℃is ±0.5℃[2 ,3]. The temperature collected by the DS18B20 is transmitted in the 1-Wire bus way, and this highly raises the system anti-jamming and makes it fit in situ 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 signal wire and the third is connected to the power. The second way is parasite power supply [5]. As the parasite power supply will lead to the complexity of the hardware circuit, the difficulty of the software control and the performance degradation of the chip, etc. But the DS18B20(s) can be connected to the I/O port of the micro controller in the external power supply way and it is more popular. Therefore the external power supply is used and the second pin is connected to the pin P1.3 of the AT89S51. Actually, if there are multipoint to be detected, the DS18B20(s) can be connected to the 1-Wire bus. But when the number is over 8, there is a concern to the driving and the more complex software design as well as the length of the 1-Wire bus. Normally it is no more than 50m. To achieve distant control, the system can be designed in to a wireless one to break the length limit of the 1-Wire bus [6].C. LCD CircuitThe LCD 12232F is used, which can be used to show characters, temperature value and time, and supply a friendly display interface. The 12232F is a LCD with 8192 128×32 pixels Chinese character database and 128 16×8 pixels ASCII character set graphics. It mainly consists of row drive/column drive and 128×32 full lattice LCD with t he function of displaying graphics as well as 7.5×2 Chinese characters. It is in a parallel or serial mode to connect to external CPU [7]. In order to economize the hardware resource, the 12232F should be connected to the AT89S51 in serial mode with only 4 output ports used. The LCD grayscale can be changed by adjusting the variable resistor connected the pin Vlcd of the LCD. CLK is used to transmit serial communication clock. SID is used to transmit serial data. CS is used to enable control the LCD. L+ is used to control the LCD backlight power.D. Clock CircuitThe Dallas DS18B20 is used, which is a high performance, low-power and real-time clock chip with RAM. The DS18B20 serves in the system with calendar clock and is used to monitor the time. The time data is read and processed by the AT89C51 and then displayed by the LCD. Also the time can be adjusted by the keyboard. The DS18B20 crystal oscillator is set at 32768Hz, and the recommended compensation capacitance is 6pF. The oscillator frequency is lower, so it might be possible not to connect the capacitor, and this would not make a big difference to the time precision. The backup power supply can be connected to a 3.6V rechargeable battery.E. Keyboard Control CircuitThe keyboard interface in the system is driven by the HD7279A which has a +5V single power supply and which is connected to the keyboard and display without using anyactive-device. According to the basic requirements and functions of the system, only 6 buttons are needed. The system's functions are set by the AT89C51 receiving the entered data. In order to save the external resistor, the 1×6 keyboard is used, and the keyboard codes are defined as: 07H, 0FH, 17H, 1FH, 27H, 2FH. The order can be read out by reading the code instruction. HD7279A is connected to the AT89S51 in serial mode and only 4 ports are 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 keyboard monitoring, decoding and key codes identification.F. Alarm CircuitIn order to simplify the circuit and convenient debugging, a 5V automatic buzzer is used in the alarm circuit [8]. And this make the software programming simplified. As shown in Fig. 7, it is controlled by the PNP transistor 9012 whose base is connected to the pin P2.5 of the AT89C51. When the temperature exceeds the upper and lower limit value, the P2.5 output low level which makes the transistor be on and then an alarm is given by the buzzer.G. Drive CircuitA step motor is used as the drive device to control the temperature. The four-phase and eight-beat pulse distribution mode is used to drive motor and the simple delay program is used to handle the time interval between the pulses to obtain different rotational speed. There are two output states for the step motor. One: when the temperature is over the upper value, the motor rotates reversely (to low the temperature), while when lower than the lower limit value, the motor rotates normally (to raise the temperature); besides not equals the preset value. Two: when the temperature is at somewhere between the two endsand equals the preset value, the motor stops. These steps are used to achieve the temperature control. In addition, the motor speed can also be adjusted by relative buttons. As shown in Fig. 8, the code data is input through ports A11~A8 (be P2.3~P2.0) of the AT89C51 and inverted output by the inverter 74LS04. Finally it is amplified by the power amplifier 2803A to power the motor.3.2 SOFTWARE DESIGNAccording to the general design requirement and hardware circuit principle of the system, as well as the improvement of the program readability, transferability and the convenient debugging, the software design is modularized. The system flow mainly includes the following 8 steps: POST (Power-on self-test), system initiation, temperature detection, alarm handling, temperature control, clock chip DS18B20 operation, LCD and keyboard operation. The main program flow is shown in Fig. 9. Give a little analysis to the above 8 tasks, it is easy to find out that the last five tasks require the real time operation. But to the temperature detection it can be achieved with timer0 timing 1 second, that is to say temperature detection occurs per second. The system initiation includes global variable definition, RAM initiation, special function register initiation and peripheral equipment initiation. Global variable definition mainly finishes the interface definition of external interface chip connected to the AT89C51, and special definition of some memory units. RAM initiation mainly refers to RAM processing. For example when the system is electrified the time code will be stored in the internal unit address or the scintillation flag will be cleared. The special function register initiation includes loading the initial value of timer and opening the interrupt. For example, when the system is electrified the timer is initialized. Theperipheral equipment initiation refers to set the initial value of peripheral equipment. For example, when the system is electrified, the LCD should be initialized, the start-up display should be called, the temperature conversion command should be issued firstly and the clock chip DS18B20 should also be initialized. The alarm handling is mainly the lowering and the raising of temperature to make the temperature remain with the preset range. When the temperature is between the upper and the lower limit value, it goes to temperature control handling, that is to say the temperature need to be raised or lowered according to the preset value. By doing so make the condition temperature equal to the preset value and hence to reach the temperature target.4 CONCLUSIONThe temperature control system has the advantages of friendly human-computer interaction interface, simple hardware, low cost, high temperature control precision (error in the range of ±1 ℃), convenience and versatility, etc. It can be widely used in the occasions with -55℃to 125℃range, and there is a certain practical value.温度控制系统的设计摘要研究了基于AT89C51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DS18B20构成。

摘要随着现代信息技术的飞速发展，温度测量控制系统在工业、农业及人们的日常生活中扮演着一个越来越重要的角色，它对人们的生活具有很大的影响，所以温度采集控制系统的设计与研究有十分重要的意义。

近年来，电风扇增设了各种新功能，既彰显了个性，也在无形中提高了档次。

电风扇起停的自动控制，能够解决夏天人们晚上熟睡时，由于夜里温度下降而导致受凉，或者从睡梦中醒来亲自开关电风扇的问题，具有重要的现实意义。

从此目的出发，本文介绍了一种基于AT89C51单片机的电风扇智能调速器的设计，该设计以AT89C51控制器为核心，巧妙利用温度传感器电路，及时而准确的采集环境温度，利用双向晶闸管对电机进行无级调速，把智能控制技术用于家用电器的控制中，用人体周围的环境温度对风扇进行温控。

关键字：电风扇，单片机，温度传感器，数码管Smart fan control system based on single chip microcomputerAuthor: Yang wanliTutor: He hongliAbstractWith the rapid development of modern information technology, temperature measuring control system play an increasingly important role in industry, agriculture and People's Daily life. It has a great influence on people's lives, so the design of the control system of temperature acquisition and research has the very vital significance.In recent years, Electric fans added lots of new features . It doesn’t reveal the individualcharacter, but in virtually it also improves the level. The automatic control of f an’s start and stop can solve the problem which when people are sleeping at night in summer, due to temperature drop and lead to catch cold at night, or waking from sleep to switch electric fan, so it has important practical significance . Therefore, the paper introduces the design of electric fan intelligent governor based on AT89C51 . The design uses AT89C51 controller as the core, skillfully using temperature sensor circuit timely and accurately to collect environment temperature, and using the two-way thyristor to stepless speed regulation of motor. The intelligent control technology is used in home appliances control, and uses the human body environment temperature to realize the control of temperature of fan.Key words: Fan，Single chip microcomputer , The temperature sensor ，Nixietube目录1绪论 (1)2芯片介绍 (2)2.1AT89C51单片机介绍 (2)2.2温度传感器DS18B20介绍 (5)3 硬件电路及系统原理分析 (8)3.1系统总体设计 (8)3.2功能描述 (8)3.3单片机最小系统电路 (10)3.4键盘控制电路 (11)3.5数码管显示电路 (12)3.6电机调速电路 (13)3.6.1 电机调速原理 (13)3.6.2 电机控制模块设计 (14)3.7报警电路 (15)4 控制器软件设计 (16)4.1主程序 (16)4.2温度传感器模块 (17)4.3电机调速与控制子模块 (18)5仿真结果 (20)结论 (23)致谢 (24)参考文献 (25)附录 (26)1绪论随着空调在日常生活中的普遍应用，很容易想到电风扇会成为空调的社会淘汰品，其实经过市场的考验和证实，事实并非如此。

外文原文Single-chip microcomputer1. the introduction of the singlechip microcomputerThe singlechip is one kind of integrated circuit chip, which uses the ultra large-scale technology and has the data-handling capacity (for example arithmetic operation, logic operation, data transfer, interrupt processing) the microprocessor (CPU), random access data-carrier storage (RAM), read-only program memory (ROM), input output circuit (I/O), possibly also includes fixed time the counter, serial passes unguardedly (SCI), demonstration actuation electric circuit (LCD or LED actuation electric circuit), pulse-duration modulation electric circuit (PWM), simulation multichannel switch and A/Electric circuit and so on D switch integrates to together the monolith chip on, constitutes to be smallest the computer system which however consummates. These electric circuits can under the software control accurate, be rapid, highly effective complete the procedure designer preset the duty. From this looked that, singlechip has the function which the microprocessor does not have, it may alone complete the intellectualization control function which the modern industry control requests, this is singlechip biggest characteristic. However singlechip also is different with the single trigger, the chip before the development, it only has the function greatly strengthened ultra large scale integrated circuit, if entrusts with it the specific procedure, it then is youngest, the integrity microcomputer control system, it (PC machine) has the essential difference with the single trigger or the personal computing, singlechip application belongs to the chip level application, needs the user to understand singlechip chip the structure and the command system as well as other integrated circuit application technologies and the system design need theory and technology, with such specific chip design application procedure, thus causes this chip to have the specific function.The different singlechip has the different hardware characteristic and the software characteristic, namely their technical characteristic is different, the hardware characteristic is decided by singlechip chip internal structure, the user must use some kind of singlechip, must understand whether this product does satisfy the characteristic target which the need the function and the application system requests. Here technical characteristic including function characteristic, control characteristic and electrical specification and so on, these information needs to obtain from in theproduction merchant technical manual. The software characteristic is refers to the command system characteristic and the development support environment, theinstruction characteristic is singlechip addressing way which we is familiar with, the data processing and the logical processing way, input-output characteristic and to power source request and so on. The development support environment is compatible and the probability including the instruction, supports the software (to contain may support development application procedure software resources) and the hardware resources. Must use some model singlechip to develop own application system, master its structure characteristic and the technical characteristic is that we need.. Singlechip control system could substitute for before uses control system which the complex electronic circuit or the digital circuit constituted, might the software control realizes, and could realize the intellectualization, now singlechip control category omnipresent, for example correspondence product, domestic electric appliances, intelligent instrument measuring appliance, process control and special-purpose control device and so on, singlechip application domain was more and more widespread. Indeed, singlechip application significance is far is not restricted in its application category or from this the economic efficiency which brings, it fundamentally changed the traditional control method and the design thought more importantly. Is controls technical a revolution, is an important milestone.2.The MCU’s development outlineIn 1946 first electronic accounting machine birth until now, only then 50 years, depends upon microelectronic technology and the semiconductor technology progress, from the electron tube - transistor- integrated circuit - large scale integrated circuit, now together on the chip definitely may integrate several million even more than ten million transistor, causes the computer volume slightly, the function is stronger. Specially in the nearly 20 years time, computer technology obtained the rapid development, the computer in the industry and agriculture, the scientific research, the education, the national defense and the aerospace domain has obtained the widespread application, computer technology already was a national modern science and technology level important symbol.Singlechip is born in the 20th century 70's, looks like F8 monolithic microcomputer which Fairchid Corporation develops. The so-called singlechip is uses the large scale integrated circuit technology the central processing element (Center Processing Unit, Also is Chang Cheng CPU) and the data-carrier storage (RAM), theprogram memory (ROM) and other I/O passes integrates unguardedly on together the chip, constitutes a smallest computer system, but modern singlechip then has added on the severance unit, fixed time unit and A/D transformation and so on more complex, more perfect electric circuit, causes singlechip the function more and more formidable, the application is more widespread.The 20th century 70's, microelectronic technology is being at the development phase, theintegrated circuit belongs to the scale development time, each kind of new material new craft not yet mature, singlechip still occupied the primary development phase, the part integration scale also quite small, the function quite was simple, CPU, RAM had generally has also included some simple I/O integrates to the chip on, looks like Farichild Corporation to belong to this type, it also must be joined to the periphery other processing electric circuits just now to constitute the integrity the computing system. The similar singlechip also has Zilog Corporation the Z80 microprocessor. In 1976 INTEL Corporation has promoted the MCS-48 singlechip, this time singlechip is the genuine 8 monolithic microcomputers, and pushes to the market. It is young by the volume, function entire, the price has lowly won the widespread application, has laid the foundation for singlechip development, becomes in singlechip history the important milestone. Under the MCS-48 leadership, after that, each big semiconductor company developed and has developed own singlechip one after another, looked like Zilog Corporation the Z8 series.To the beginning of the 80's, singlechip has developed to the high performance stage, looks like INTEL Corporation the MCS-51 series, Motorola Corporation 6,801 and 6,802 series, Rokwell Corporation 6,501 and 6,502 series and so on, In addition,Japan's famous electrical company NEC and HITACHI all one after another developed had oneself characteristic the special-purpose singlechip. The 80's, world each big company competes to develop the variety multi-purpose strong singlechip, some severaldozens series, more than 300 varieties, this time singlechip belongs approximately truely monolithic, mostly integrated CPU, RAM, ROM, number many I/O connection, many kinds of interruption system, even also has some to bring A/D switch singlechip, function more and more formidable, RAM and ROM capacity also more and more big, the addressing space even may reach 64kB, may say, singlechip developed to a brand-new stage, the application domain has beenmore widespread, many domestic electric appliances moved towards the intellectualized development path which controlled using singlechip. After 1982, 16 singlechips are published, represent the product are INTEL Corporation's MCS-96 series, 16 singlechips compare 8 machine, the data width increased a time, real-time processing ability stronger, the basic frequency is higher, the integration rate had achieved 120,000 transistors, RAM increased to 232 bytes, ROM then has achieved 8kB, and had 8 interrupt sources, at the same time has disposed multichannel A/D transformation channel, high speed I/The O processing unit, is suitable for the more complex control system.After 90's, singlechip obtained the rapid development, the world each big semiconductor company has developed a function more formidable singlechip one after another. American Microchip Corporation had issued one kind of incompatible MCS-51 newgeneration of PIC series singlechip, has aroused the field widespread interest completely, its product only then 33 simplified the set of instructions to attract many users specially, caused the people to concentrate from the INTEL 111 complex instructions. The PIC singlechip has obtained the fast development, holds the small space in the field. The afterwards matter, the familiar singlechip public figures quite have been all clear, more monolithic aircraft types pour out, MOTOROLA Corporation had issued one after another the MC68HC series singlechip, Japan's several famous companies all developed a performance stronger product, but Japan's singlechip used in generally the special-purpose systems control, but did not look like company and so on INTEL puts in to the market forms the general singlechip. For example NEC Corporation produces the uCOM87 series singlechip, its representative works uPC7811 is one kind of performance quite outstanding singlechip. MOTOROLA Corporation's characteristic and so on MC68HC05 series its high speed low price has won many users. Zilog Corporation's Z8 series product representative works are Z8671, contains BASIC the Debug interpreter, enormous place then user. But American country half COP800 series singlechip then uses the advanced Harvard structure. ATMEL Corporation then perfectly unifies singlechip technology and the advanced Flash memory technology, has issued the performance quite outstanding AT89 series singlechip. Including company and so on China's Taiwan HOLTEK and WINBOND in abundance has also joined singlechip development ranks, by reason of their inexpensive superiority, shares cup of beautiful thick soup.In 1990 American INTEL Corporation promoted 80,960 super 32 singlechips to cause the computer stir, the product has put in the market one after another, became in singlechip history an important milestone. This period, in singlechip field, singlechip variety extraordinary splendour, competes to be the most unusual. Some 8, 16 even 32 machine, but 8 singlechips by its price inexpensive, the variety complete, the application software rich, the support environment were still full, characteristic and so on development convenience but are occupying the dominant position. But INTEL Corporation by reason of their abundant technology, the performance outstanding type and the good foundation, at present was still singlechip mainstream product. Only is the 90's intermediate stages, INTEL Corporation is busy is developing their personal computing microprocessor, not the enough energy continued singlechip technology which develops oneself creates leads, but by company and so on PHILIPS continues to develop the C51 series singlechip.3.Singlechip application domainSinglechip widely applies in the instrument measuring appliance, the domestic electric appliances, the medical equipment, domain and so on aerospace, special purpose equipment intellectualized management and process control, may divide the following several categoriesapproximately:(1). On intelligent instrument measuring appliance applicationSinglechip has the volume small, the power loss low, the control function strong, the expansion is nimble, merit and so on microminiaturization and easy to operate, widely applies in the instrument measuring appliance, the union different type sensor, may realize such as physical quantity the and so on voltage, power, frequency, humidity, temperature, current capacity, speed, thickness, angle, length, degree of hardness, element, pressure survey. Uses singlechip control to cause the instrument measuring appliance digitization, the intellectualization, the microminiaturization, also the function compares uses the electron or the digital circuit is more formidable. For example precise measurement equipment (dynamometer, oscilloscope, each kind of analyzer).(2). In industry control applicationMay constitute the various formats control system, the data acquisition system with singlechip. For example the factory assembly line intellectualized management, the elevator intellectualization control, each kind of alarm system, constitutes two cascade control systems with the computer networking and so on.(3).In domestic electric appliances applicationMay say like this that, the present domestic electric appliances basically have all used singlechip control, praised, the washer, the electric refrigerator, the air conditioner, the color television, other acoustic video frequency equipments from the electricity food, again to the electronic weighting equipment, all kinds of, omnipresent.(4).In computer network and correspondence domain applicationOf the modern singlechip has the correspondence connection generally, may very conveniently and the computer carries on the data communication,for provided the extremely good physical conditions application in between the computer network and the communication facility, the present communication facility basically has all realized singlechip intelligence control, from the handset, the telephone, the small program controlled switch, the building automatic correspondence ringing system, the train wireless correspondence, again the mobile phone which everywhere to the routine work in, the colony mobile communication, radio intercom and so on.(5).Singlechip in medical equipment domain applicationSinglechip quite is also widespread inmedical equipment use, for example medical life-support machine, each kind of analyzer, , ultrasound diagnosis equipment and hospital bed ringing system and so on. In addition, singlechip in the industry and commerce, the finance, the scientific research, the education, domain and so on national defense aerospaceall has the extremely widespread use.4.Singlechip development tendencyNow may say singlechip was all flowers blooms together, the time which hundred school of thought contended, in the world each big chip manufacture company has all promoted own singlechip, from 8, 16 to 32, innumerable, had everything expected to find, has compatibly with the mainstream C51 series, also had not not compatibly, but they unique, became mutually supplementarily, provided the broad world for singlechip application. Looks over singlechip developing process, may indicate singlechip development tendency, has approximately:(1). Low power loss CMOSThe MCS-51 series 8,031 promotes when the power loss reaches 630mW, but the present singlechip all about 100mW, along with more and more is generally low to singlechip power loss request, the present each singlechip manufacturer basic has all used CMOS (complementary metal oxide semiconductor craft). Looked like80C51 to use HMOS (namely high density metal oxide compound semiconductor craft) and CHMOS (supplementary high density metal oxide compound semiconductor craft). CMOS although power loss low, but because its physical characteristic decides its working speed insufficiently high, but CHMOS then had has been high speed and the low power loss characteristic, these characteristics, suited in are requesting the low power loss likely battery power supply the application situation. Therefore this kind of craft will be the main way which the next section of times singlechip will develop.(2). Miniature monolithicNow the conventional singlechip all is generally the central processor (CPU), the random access data storage (RAM), the read-only program memory (ROM), parallel and the serial communication connection, the interruption system, the timing circuit, the clock electric circuit integration on together the sole chip, the enlargement mode singlechip integrated like A/The D switch, PMW (pulse-duration modulation electric circuit), WDT (watch-dog), some singlechips (liquid crystal) actuate LCD the electric circuit all to integrate on the sole chip, such singlechip contains unit electric circuit more, the function is more formidable. Even singlechip merchant also may act according to the user requiremnet the body custom make, makes has oneself characteristic singlechip chip. In addition, present product universal demand volume small, weight light, this requests singlechip strong and the power loss is low besides the function, but also requests its volume to have to be small. Present many singlechips all have the many kinds of seals form, SMD (superficial seal) more and more receives welcome, to enable the system which constitutes by singlechip towards themicrominiaturized direction to develop.(3).Mainstream and multi- varieties coexistenceNow although singlechip variety is many, unique, but still as the core singlechip occupies the mainstream take 80C51, the compatible its structure and the command system have PHILIPS Corporation the product, the ATMEL Corporation's product and the Chinese Taiwan's Winbond series singlechip. Therefore C8051 was the core singlechip occupied the half of the country. But Microchip Corporation's PIC simplified the set of instructions (RISC) also to have the strong development tendency, the Chinese Taiwan's HOLTEK Corporation recent years singlechip output grows day by day, if the low price nature superior superiority, occupied a certain market minute volume. In addition also has MOTOROLA Corporation the product, the Japaneseseveral big companies' special-purpose singlechips. In the certain time, this kind of situation will be able to continue, will not have the monopoly aspect which some singlechip unified, will walk will be depends on for existence supplementarily, will complement one another, the communal development path.中文翻译单片机1. 单片机介绍单片机是一种集成电路芯片，应用超大规模技术把具有数据处理能力(如算术运算，逻辑运算、数据传送、中断处理)的微处理器(CPU)，随机存取数据存储器(RAM)，只读程序存储器(ROM)，输入输出电路(I/O口)，可能还包括定时计数器，串行通信口(SCI)，显示驱动电路(LCD 或 LED 驱动电路)，脉宽调制电路(PWM)，模拟多路转换器A/D 转换器等电路集成到一块单块芯片上,构成一个最小然而完善的计算机系统。

目录摘要 (1)1 绪论 (2)1.1 课题背景 (2)1.2 课题研究的目的和意义 (3)1.3 系统的设计要求及内容 (3)2 电风扇系统的方案论证 (3)2.1 保护电路的选择 (3)2.2 控制核心的选择 (4)2.3 显示电路的选择 (5)3 系统的主要硬件电路设计 (5)3.1 总体硬件设计 (5)3.2 过热检测模块的设计 (8)3.3 电机调速与控制模块设计 (9)3.4 显示与控制模块设计 (10)3.5 键盘模块设计 (11)4 系统程序设计及仿真 (12)4.1 主程序流程图设计 (12)4.2 定时器T0中断程序流程图设计 (13)4.3 A/D转换测量子程序流程图设计 (14)4.4 系统仿真结果 (15)4.5 源程序 (15)结论 (15)致谢 (15)参考文献 (15)附录A：单片机电风扇控制系统的设计原理图 (16)附录B：仿真结果图 (17)附录C：参考程序 (22)基于单片机的电风扇控制系统的设计电子信息科学与技术专业学生：指导老师：摘要：本论文设计了一个单片机电风扇控制系统。

系统采用MCS-52单片机为控制核心，设计了按键电路、显示电路和过热保护电路,并采用C语言进行编程、调试和仿真，实现了电风扇的几项基本功能：电机的正反转功能，0-990秒的定时功能，以及自然、正常、睡眠三种风类的选择功能。

经过多次的测试与电路的调整、系统的各项功能均能正常实现。

关键词：MCS-52,电风扇，保护电路,定时Design of the electric fan controller systembased on MCUElectronics and Information Science and TechnologyCandidate: CAO QiwenAdvisor: PENG JianyingAbstract：In this paper,it designed an electric fan controller system based on MCU.The system used MCS-52 microcontroller as the core of control, designed the key circuit, display circuit and overheating protection circuit which used C language to complete the programm, test and simulation,it has realized a few basic function of electric fan : reversing function, fixed time of 0-990 seconds and three kinds of wind selecting which are natural,normal and sleepy.After many tests and improvement, all of the functions can work natually.Keywords：MCU,Electric fan,Protection circuit,Fixed time1绪论1.1 课题背景电风扇在我国，是80年代开始兴起的一种小型的家用电器，刚开始它的功能单一，而且耗电量大，随着技术的不断更新，它的功能更加强大，更加趋于人性化。

中文1880字电子信息科学系外文翻译（2012届）基于单片机的电动保护控制器系统的设计学生姓名学号专业班级指导教师完成日期一、外文原文：A.C. Motor ProtectionAREVAINTRODUCTIONThere are a wide range of a.c. motors and motor characteristics in existence, because of the numerous duties for which they are used.All motors need protection, but fortunately, the more fundamental problems affecting the choice of protection are independent of the type of motor and the type of load to which it is connected. There are some important differences between the protection of induction motors and synchronous motors.Motor characteristics must be carefully considered when applying protection; while this may be regarded as stating the obvious, it is emphasised because it applies more to motors than to other items of power system plant. For example, the starting and stalling currents/times must be known when applying overload protection, and furthermore the thermal withstand of the machine under balanced and unbalanced loading must be clearly defined.The conditions for which motor protection is required can be divided into two broad categories: imposed external conditions and internal faults.THERMAL(OVERLOAD) PROTECTIONThe majority of winding failures are either indirectly or directly caused by overloading (either prolonged or cyclic), operation on unbalanced supply voltage, or single phasing, which all lead through excessive heating to the deterioration of the winding insulation until an electrical fault occurs. The generally accepted rule is that insulation life is halved for each 10°C rise in temperature above the rated value, modified by the length of time spent at the higher temperature. As an electrical machine has a relatively large heat storage capacity, it follows that infrequent overloads of short duration may not adversely affect the machine. However, sustained overloads of only a few percent may result in premature ageing and insulation failure.Furthermore, the thermal withstand capability of the motor is affected by heating in the winding prior to a fault. It is therefore important that the relay characteristic takes account of the extremes of zero and full-load pre-fault current known respectively as the 'Cold' and 'Hot' conditions.{}⎥⎦⎤⎢⎣⎡-=2)/(11log I I t R e τThe variety of motor designs, diverse applications, variety of possible abnormal operating conditions and resulting modes of failure result in a complex thermal relationship. A generic mathematical model that is accurate is therefore impossible to create. However, it is possible to develop an approximate model if it is assumed that the motor is a homogeneous body, creating and dissipating heat at a rate proportional to temperature rise. This is the principle behind the ‘thermal replica’ model of a motor used for overload protection. The temperature T at any instant is given by:)(max τt e I T T --=where:max T =final steady state temperatureτ=hrating time constant Temperature rise is proportional to the current squared:)1(2τt R e KI T --=where:R I =current which,if flowing continuously,produces temperature max T inthe motor.Therefore, it can be shown that, for any overload current I , the permissible time t for this current to flow is:In general, the supply to which a motor is connected may contain both positive and negative sequence components, and both components of current give rise to heating in the motor. Therefore, the thermal replica should take into account both of these components, a typical equation for the equivalent current being:)(2221KI I I eq += Where:1I =positive sequence current2I =negative sequence currentAnd:K =negative sequence rotor resistance/positive sequence rotor resistanceAt rated speed. A typical value of K is 3.Finally, the thermal replica model needs to take into account the fact that the motor will tend to cool down during periods of light load, and the initial state of themotor. The motor will have a cooling time constant r τthat defines the rate of cooling. Hence, the final thermal model can be expressed as:)1/()(log 222--=k A k t e τ…Equation 19.1Where:τ=heating time constant2A = initial state of motor (cold or hot)th I =thermal setting currentEquation 19.1 takes into account the ‘cold’ and ‘hot’ characteristics defined in IEC 60255, part 8.Some relays may use a dual slope characteristic for the heating time constant, and hence two values of the heating time constant are required. Switching between the two values takes place at a pre-defined motor current. This may be used to obtain better tripping performance during starting on motors that use a star- delta starter. During starting, the motor windings carry full line current, while in the ‘run’ condition, they carry only 57% of the current seen by the relay. Similarly, when the motor is disconnected from the supply, the heating time constant τ is set equal to the cooling time constant r τ.Since the relay should ideally be matched to the protected motor and be of capable close sustained overload protection, a wide range of relay adjustment is desirable together with good accuracy and low thermal overshoot.SHORT-CIRCUIT PROTECTIONMotor short-circuit protection is often provided to cater for major stator winding faults and terminal flashovers. Because of the relatively greater amount of insulation between phase windings, faults between phases seldom occur. As the stator windings are completely enclosed in grounded metal, the fault would very quickly involve earth, which would then operate the instantaneous earth fault protection. A single definite time over current relay element is all that is required for this purpose, set to about 125% of motor starting current. The time delay is required to prevent spurious operation due to CT spill currents, and is typically set at 100ms. If the motor is fed from a fused contactor, co-ordination is required with the fuse, and this will probably involve use of a long time delay for the relay element. Since the object of the protection is to provide rapid fault clearance to minimize damage theqI I k =caused by the fault, the protection is effectively worthless in these circumstances. It is therefore only provided on motors fed via circuit breakers.Differential (unit) protection may be provided on larger HV motors fed via circuit breakers to protect against phase- phase and phase-earth faults, particularly where the power system is resistance-earthed. Damage to the motor in case of a fault is occurring minimized, as the differential protection can be made quite sensitive and hence detects faults in their early stages. The normal definite time over current protection would not be sufficiently sensitive, and sensitive earth fault protection may not be provided. The user may wish to avoid the detailed calculations required of capacitance current in order to set sensitive non-directional earth fault over current protection correctly on HV systems (Chapter 9) or there may be no provision for a VT to allow application of directional sensitive earth fault protection. There is still a lower limit to the setting that can be applied, due to spill currents from CT saturation during starting, while on some motors, neutral current has been found to flow during starting, even with balanced supply voltages that would cause the differential protection to operate. For details on the application of differential protection, refer to Chapter 10. However, non-directional earth fault over current protection will normally be cheaper in cases where adequate sensitivity can be provided.UNDER VOLTAGE PROTECTIONMotors may stall when subjected to prolong under voltage conditions. Transient under voltages will generally allow a motor to recover when the voltage is restored, unless the supply is weak.Motors fed by contactors have inherent under voltage protection, unless a latched contactor is used. Where a specific under voltage trip is required, a definite time under voltage element is used. If two elements are provided, alarm and trip settings can be used. An interlock with the motor starter is required to block relay operation when the starting device is open, otherwise a start will never be permitted. The voltage and time delay settings will be system and motor dependent. They must allow for all voltage dips likely to occur on the system during transient faults, starting of motors, etc. to avoid spurious trips. As motor starting can result in a voltage depression to 80% of nominal, the voltage setting is likely to be below this value. Re-acceleration is normally possible for voltage dips lasting between 0.5-2 seconds, depending on system, motor and drive characteristics, and therefore the time delaywill be set bearing these factors in mind.LOSS-OF-LOAD PROTECTIONLoss-of-load protection has a number of possible functions. It can be used to protect a pump against becoming unprimed, or to stop a motor in case of a failure in a mechanical transmission (e.g. conveyor belt), or it can be used with synchronous motors to protect against loss-of-supply conditions. Implementation of the function is by a low forward power relay element, interlocked with the motor starting device to prevent operation when the motor is tripped and thus preventing a motor start. Where starting against a very low load (e.g. a compressor), the function may also need to be inhibited for the duration of the start, to prevent the maloperation.The setting will be influenced by the function to be performed by the relay.A time delay may be required after pickup of the element to prevent operation during system transients. This is especially important for synchronous motor loss-of supply protection.二、翻译内容：交流电机保护阿海珐集团引言交流电动机因为应用的范围很广，并且拥有较好的电动机特性，所以被用来完成许多任务。

外文文献原稿和译文原稿The Description of AT89S511 General DescriptionThe AT89S51 is a low-power, high-performance CMOS 8-bit microcontroller with 4K bytes of In-System Programmable Flash memory. The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with In-System Programmable Flash on a monolithic chip, the Atmel AT89S51 is a powerful microcontroller which provides a highly-flexible and cost-effective solution to many embedded control applications.The AT89S51 provides the following standard features: 4K bytes of Flash, 128 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, two 16-bit timer/counters, a five-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes.The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next external interrupt or hardware reset.2 PortsPort 0 is an 8-bit open drain bi-directional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high-impedance inputs. Port 0 can also be configured to be the multiplexed low-order address/data bus during accesses to external program and data memory. In this mode, P0 has internal pull-ups. Port 0 also receives the code bytes during Flashprogramming and outputs the code bytes during program verification. External pull-ups are required during program verification.Port 1 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (I IL) because of the internal pull-ups.Port 1 also receives the low-order address bytes during Flash programming and verification.Port 2 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (I IL) because of the internal pull-ups.Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX @ DPTR). In this application, Port 2 uses strong internal pull-ups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-order address bits and some control signals during Flash programming and verification.Port 3 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (I IL) because of the pull-ups. Port 3 receives some control signals for Flash programming and verification. Port 3 also serves the functions of various special features of the AT89S51, as shown in thefollowing table.3 Special Function RegistersA map of the on-chip memory area called the Special Function Register (SFR) space is shown in Table 3-1.0F0H 0F7H0E8H 0EFH0E0H 0E7H0D8H 0DFH0D0H 0D7H0C8H 0CFH 0C0H 0C7H 0B8H 0BFH 0B0H 0B7H 0A8H 0AFH0A0H0A7H98H 9FH 90H 97H 88H 8FH80H87HNote that not all of the addresses are occupied, and unoccupied addresses may not be implemented on the chip. Read accesses to these addresses will in general return random data, and write accesses will have an indeterminate effect.User software should not write 1s to these unlisted locations, since they may be used in future products to invoke new features. In that case, the reset or inactive values of the new bits will always be 0.Interrupt Registers: The individual interrupt enable bits are in the IE register. Two priorities can be set for each of the five interrupt sources in the IP register.Table 3-2. AUXR:Auxiliary RegisterAUXR Address=8EH Reset Value=XXX00XX0bBitReserved for future expansionDISALE Disable/Enable ALEDISALEOperating Mode0 ALE is emitted at a constant rate of 1/6 the oscillator frequency1 ALE is active only during a MOVX or MOVC instruction DISRTO Disable/Enable Reset-outDISRTO0 Reset pin is driven High after WDT times out1 Reset pin is input onlyWDIDLE Disable/Enable WDT in IDLE modeWDIDLE0 WDT continues to count in IDLE mode1 WDT halts counting in IDLE modeDual Data Pointer Registers: To facilitate accessing both internal and external data memory, two banks of 16-bit Data Pointer Registers are provided: DP0 at SFR address locations 82H-83H and DP1 at 84H-85H. Bit DPS = 0 in SFR AUXR1 selects DP0 and DPS = 1 selects DP1. The user should always initialize the DPS bit to the appropriate value before accessing the respective Data Pointer Register.Power Off Flag: The Power Off Flag (POF) is located at bit 4 (PCON.4) in the PCON SFR. POF is set to “1” during power up. It can be set and rest under software control and is not affected by reset.4 Memory OrganizationMCS-51 devices have a separate address space for Program and Data Memory. Up to 64K bytes each of external Program and Data Memory can be addressed.4.1 Program MemoryIf the EA pin is connected to GND, all program fetches are directed to external memory. On the AT89S51, if EA is connected to V CC, program fetches to addresses 0000H through FFFH are directed to internal memory and fetches to addresses 1000H through FFFFH are directed to external memory.4.2 Data MemoryThe AT89S51 implements 128 bytes of on-chip RAM. The 128 bytes are accessible via direct and indirect addressing modes. Stack operations are examples of indirect addressing, so the 128 bytes of data RAM are available as stack space.5 Watchdog Timer (One-time Enabled with Reset-out)The WDT is intended as a recovery method in situations where the CPU may be subjected to software upsets. The WDT consists of a 14-bit counter and the Watchdog Timer Reset (WDTRST) SFR. The WDT is defaulted to disable from exiting reset. Toenable the WDT, a user must write 01EH and 0E1H in sequence to the WDTRST register (SFR location 0A6H). When the WDT is enabled, it will increment every machine cycle while the oscillator is running. The WDT timeout period is dependent on the external clock frequency. There is no way to disable the WDT except through reset (either hardware reset or WDT overflow reset). When WDT overflows, it will drive an output RESET HIGH pulse at the RST pin.5.1 Using the WDTTo enable the WDT, a user must write 01EH and 0E1H in sequence to the WDTRST register (SFR location 0A6H). When the WDT is enabled, the user needs to service it by writing 01EH and 0E1H to WDTRST to avoid a WDT overflow. The 14-bit counter overflows when it reaches 16383 (3FFFH), and this will reset the device. When the WDT is enabled, it will increment every machine cycle while the oscillator is running. This means the user must reset the WDT at least every 16383 machine cycles. To reset the WDT the user must write 01EH and 0E1H to WDTRST. WDTRST is a write-only register. The WDT counter cannot be read or written. When WDT overflows, it will generate an output RESET pulse at the RST pin. The RESET pulse duration is 98xTOSC, where TOSC = 1/FOSC. To make the best use of the WDT, it should be serviced in those sections of code that will periodically be executed within the time required to prevent a WDT reset.5.2 WDT DURING Power-down and IdleIn Power-down mode the oscillator stops, which means the WDT also stops. While in Power-down mode, the user does not need to service the WDT. There are two methods of exiting Power-down mode: by a hardware reset or via a level-activated external interrupt, which is enabled prior to entering Power-down mode. When Power-down is exited with hardware reset, servicing the WDT should occur as it normally does whenever the AT89S51 is reset. Exiting Power-down with an interrupt is significantly different. The interrupt is held low long enough for the oscillator to stabilize. When the interrupt is brought high, the interrupt is serviced. To prevent the WDT from resetting the device while the interrupt pin is held low, the WDT is not started until the interrupt is pulled high. It is suggested that the WDT be reset during the interrupt service for the interrupt used to exit Power-down mode. To ensure that the WDT does not overflow within a few states of exiting Power-down, itis best to reset the WDT just before entering Power-down mode. Before going into the IDLE mode, the WDIDLE bit in SFR AUXR is used to determine whether the WDT continues to count if enabled. The WDT keeps counting during IDLE (WDIDLE bit = 0) as the default state. To prevent the WDT from resetting the AT89S51 while in IDLE mode, the user should always set up a timer that will periodically exit IDLE, service the WDT, and reenter IDLE mode.With WDIDLE bit enabled, the WDT will stop to count in IDLE mode and resumes the count upon exit from IDLE.6.InterruptsThe AT89S51 has a total of five interrupt vectors: two external interrupts (INT0 and INT1), two timer interrupts (Timers 0 and 1), and the serial port interrupt. These interrupts are all shown in Figure 6-1. Each of these interrupt sources can be individually enabled or disabled by setting or clearing a bit in Special Function Register IE. IE also contains a global disable bit, EA, which disables all interrupts at once.Note that Table 6-1 shows that bit positions IE.6 and IE.5 are unimplemented. User software should not write 1s to these bit positions, since they may be used in future AT89 products. The Timer 0 and Timer 1 flags, TF0 and TF1, are set at S5P2 of the cycle in which the timers overflow. The values are then polled by the circuitry in the next cycle.Figure 6-1 Interrupt Sources7 Oscillator CharacteristicsXTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier that can be configured for use as an on-chip oscillator, as shown in Figure 7-1. Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven, as shown in Figure 7-2. There are no requirements on the duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications must be observed.Figure 7-1 Oscillator ConnectionsNote: pF,1±=for Crystals2pF30CC10=for Ceramic Resonators40±pFpF10Figure 7-2 External Clock Drive Configuration8 Idle ModeIn idle mode, the CPU puts itself to sleep while all the on-chip peripherals remain active. The mode is invoked by software. The content of the on-chip RAM and all the special function registers remain unchanged during this mode. The idle mode can be terminated by any enabled interrupt or by a hardware reset.Note that when idle mode is terminated by a hardware reset, the device normally resumes pro-gram execution from where it left off, up to two machine cycles before the internal reset algorithm takes control. On-chip hardware inhibits access to internal RAM in this event, but access to the port pins is not inhibited. To eliminate the possibility of an unexpected write to a port pin when idle mode is terminated by a reset, the instruction following the one that invokes idle mode should not write to a port pin or to external memory.9 Power-down ModeIn the Power-down mode, the oscillator is stopped, and the instruction that invokes Power-down is the last instruction executed. The on-chip RAM and Special Function Registers retain their values until the Power-down mode is terminated. Exit from Power-down mode can be initiated either by a hardware reset or by activation of an enabled external interrupt (INT0 or INT1). Reset redefines the SFRs but does not change the on-chip RAM. The reset should not be activated before VCC is restored to its normal operating level and must be held active long enough to allow the oscillator to restart and stabilize.译文AT89S51概述1 一般概述该AT89S51是一个低功耗，高性能CMOS 8位微控制器,可在4K字节的系统内编程的闪存存储器。

电风扇关于智能电风扇的外文翻译电风扇关于智能电风扇的外文翻译2010-12-14求关于智能电风扇方面的外文翻译?有的发我邮箱***************不甚感激smart fan modules and syst document type and number：united states patent 6592449 abstract：a fan module including：two or more individual fans,each fan having an air movent means and amotor engaged with the air movent means for accelerating airentering each of the two or more individual fans；a tperature sensor for sensing atperature associated with the two or more fans and for outputting afirst signal corresponding to the tperature；rotational speed sensor for outputting asecond signal corresponding toarotational speed of each of the two or more fans；and aprocessor for receiving the first and second signals and controlling the two or more individual fans based on the first and second signals.功能描述本设计主要目标是使普通的电风扇的功能更加强大,使操作简单化、智能化,主要实现以下几个部分的功能：温度智控功能：风扇可以感知环境的温度,以调节风扇的转速,达到更好的工作效果。

外文原文Single-chip microcomputer1. the introduction of the singlechip microcomputerThe singlechip is one kind of integrated circuit chip, which uses the ultra large-scale technology and has the data-handling capacity (for example arithmetic operation, logic operation, data transfer, interrupt processing) the microprocessor (CPU), random access data-carrier storage (RAM), read-only program memory (ROM), input output circuit (I/O), possibly also includes fixed time the counter, serial passes unguardedly (SCI), demonstration actuation electric circuit (LCD or LED actuation electric circuit), pulse-duration modulation electric circuit (PWM), simulation multichannel switch and A/Electric circuit and so on D switch integrates to together the monolith chip on, constitutes to be smallest the computer system which however consummates. These electric circuits can under the software control accurate, be rapid, highly effective complete the procedure designer preset the duty. From this looked that, singlechip has the function which the microprocessor does not have, it may alone complete the intellectualization control function which the modern industry control requests, this is singlechip biggest characteristic. However singlechip also is different with the single trigger, the chip before the development, it only has the function greatly strengthened ultra large scale integrated circuit, if entrusts with it the specific procedure, it then is youngest, the integrity microcomputer control system, it (PC machine) has the essential difference with the single trigger or the personal computing, singlechip application belongs to the chip level application, needs the user to understand singlechip chip the structure and the command system as well as other integrated circuit application technologies and the system design need theory and technology, with such specific chip design application procedure, thus causes this chip to have the specific function.The different singlechip has the different hardware characteristic and the software characteristic, namely their technical characteristic is different, the hardware characteristic is decided by singlechip chip internal structure, the user must use some kind of singlechip, must understand whether this product does satisfy the characteristic target which the need the function and the application system requests. Here technical characteristic including function characteristic, control characteristic and electrical specification and so on, these information needs to obtain from in theproduction merchant technical manual. The software characteristic is refers to the command system characteristic and the development support environment, theinstruction characteristic is singlechip addressing way which we is familiar with, the data processing and the logical processing way, input-output characteristic and to power source request and so on. The development support environment is compatible and the probability including the instruction, supports the software (to contain may support development application procedure software resources) and the hardware resources. Must use some model singlechip to develop own application system, master its structure characteristic and the technical characteristic is that we need.. Singlechip control system could substitute for before uses control system which the complex electronic circuit or the digital circuit constituted, might the software control realizes, and could realize the intellectualization, now singlechip control category omnipresent, for example correspondence product, domestic electric appliances, intelligent instrument measuring appliance, process control and special-purpose control device and so on, singlechip application domain was more and more widespread. Indeed, singlechip application significance is far is not restricted in its application category or from this the economic efficiency which brings, it fundamentally changed the traditional control method and the design thought more importantly. Is controls technical a revolution, is an important milestone.2.The MCU’s development outlineIn 1946 first electronic accounting machine birth until now, only then 50 years, depends upon microelectronic technology and the semiconductor technology progress, from the electron tube - transistor- integrated circuit - large scale integrated circuit, now together on the chip definitely may integrate several million even more than ten million transistor, causes the computer volume slightly, the function is stronger. Specially in the nearly 20 years time, computer technology obtained the rapid development, the computer in the industry and agriculture, the scientific research, the education, the national defense and the aerospace domain has obtained the widespread application, computer technology already was a national modern science and technology level important symbol.Singlechip is born in the 20th century 70's, looks like F8 monolithic microcomputer which Fairchid Corporation develops. The so-called singlechip is uses the large scale integrated circuit technology the central processing element (Center Processing Unit, Also is Chang Cheng CPU) and the data-carrier storage (RAM), theprogram memory (ROM) and other I/O passes integrates unguardedly on together the chip, constitutes a smallest computer system, but modern singlechip then has added on the severance unit, fixed time unit and A/D transformation and so on more complex, more perfect electric circuit, causes singlechip the function more and more formidable, the application is more widespread.The 20th century 70's, microelectronic technology is being at the development phase, theintegrated circuit belongs to the scale development time, each kind of new material new craft not yet mature, singlechip still occupied the primary development phase, the part integration scale also quite small, the function quite was simple, CPU, RAM had generally has also included some simple I/O integrates to the chip on, looks like Farichild Corporation to belong to this type, it also must be joined to the periphery other processing electric circuits just now to constitute the integrity the computing system. The similar singlechip also has Zilog Corporation the Z80 microprocessor. In 1976 INTEL Corporation has promoted the MCS-48 singlechip, this time singlechip is the genuine 8 monolithic microcomputers, and pushes to the market. It is young by the volume, function entire, the price has lowly won the widespread application, has laid the foundation for singlechip development, becomes in singlechip history the important milestone. Under the MCS-48 leadership, after that, each big semiconductor company developed and has developed own singlechip one after another, looked like Zilog Corporation the Z8 series.To the beginning of the 80's, singlechip has developed to the high performance stage, looks like INTEL Corporation the MCS-51 series, Motorola Corporation 6,801 and 6,802 series, Rokwell Corporation 6,501 and 6,502 series and so on, In addition,Japan's famous electrical company NEC and HITACHI all one after another developed had oneself characteristic the special-purpose singlechip. The 80's, world each big company competes to develop the variety multi-purpose strong singlechip, some severaldozens series, more than 300 varieties, this time singlechip belongs approximately truely monolithic, mostly integrated CPU, RAM, ROM, number many I/O connection, many kinds of interruption system, even also has some to bring A/D switch singlechip, function more and more formidable, RAM and ROM capacity also more and more big, the addressing space even may reach 64kB, may say, singlechip developed to a brand-new stage, the application domain has beenmore widespread, many domestic electric appliances moved towards the intellectualized development path which controlled using singlechip. After 1982, 16 singlechips are published, represent the product are INTEL Corporation's MCS-96 series, 16 singlechips compare 8 machine, the data width increased a time, real-time processing ability stronger, the basic frequency is higher, the integration rate had achieved 120,000 transistors, RAM increased to 232 bytes, ROM then has achieved 8kB, and had 8 interrupt sources, at the same time has disposed multichannel A/D transformation channel, high speed I/The O processing unit, is suitable for the more complex control system.After 90's, singlechip obtained the rapid development, the world each big semiconductor company has developed a function more formidable singlechip one after another. American Microchip Corporation had issued one kind of incompatible MCS-51 newgeneration of PIC series singlechip, has aroused the field widespread interest completely, its product only then 33 simplified the set of instructions to attract many users specially, caused the people to concentrate from the INTEL 111 complex instructions. The PIC singlechip has obtained the fast development, holds the small space in the field. The afterwards matter, the familiar singlechip public figures quite have been all clear, more monolithic aircraft types pour out, MOTOROLA Corporation had issued one after another the MC68HC series singlechip, Japan's several famous companies all developed a performance stronger product, but Japan's singlechip used in generally the special-purpose systems control, but did not look like company and so on INTEL puts in to the market forms the general singlechip. For example NEC Corporation produces the uCOM87 series singlechip, its representative works uPC7811 is one kind of performance quite outstanding singlechip. MOTOROLA Corporation's characteristic and so on MC68HC05 series its high speed low price has won many users. Zilog Corporation's Z8 series product representative works are Z8671, contains BASIC the Debug interpreter, enormous place then user. But American country half COP800 series singlechip then uses the advanced Harvard structure. ATMEL Corporation then perfectly unifies singlechip technology and the advanced Flash memory technology, has issued the performance quite outstanding AT89 series singlechip. Including company and so on China's Taiwan HOLTEK and WINBOND in abundance has also joined singlechip development ranks, by reason of their inexpensive superiority, shares cup of beautiful thick soup.In 1990 American INTEL Corporation promoted 80,960 super 32 singlechips to cause the computer stir, the product has put in the market one after another, became in singlechip history an important milestone. This period, in singlechip field, singlechip variety extraordinary splendour, competes to be the most unusual. Some 8, 16 even 32 machine, but 8 singlechips by its price inexpensive, the variety complete, the application software rich, the support environment were still full, characteristic and so on development convenience but are occupying the dominant position. But INTEL Corporation by reason of their abundant technology, the performance outstanding type and the good foundation, at present was still singlechip mainstream product. Only is the 90's intermediate stages, INTEL Corporation is busy is developing their personal computing microprocessor, not the enough energy continued singlechip technology which develops oneself creates leads, but by company and so on PHILIPS continues to develop the C51 series singlechip.3.Singlechip application domainSinglechip widely applies in the instrument measuring appliance, the domestic electric appliances, the medical equipment, domain and so on aerospace, special purpose equipment intellectualized management and process control, may divide the following several categoriesapproximately:(1). On intelligent instrument measuring appliance applicationSinglechip has the volume small, the power loss low, the control function strong, the expansion is nimble, merit and so on microminiaturization and easy to operate, widely applies in the instrument measuring appliance, the union different type sensor, may realize such as physical quantity the and so on voltage, power, frequency, humidity, temperature, current capacity, speed, thickness, angle, length, degree of hardness, element, pressure survey. Uses singlechip control to cause the instrument measuring appliance digitization, the intellectualization, the microminiaturization, also the function compares uses the electron or the digital circuit is more formidable. For example precise measurement equipment (dynamometer, oscilloscope, each kind of analyzer).(2). In industry control applicationMay constitute the various formats control system, the data acquisition system with singlechip. For example the factory assembly line intellectualized management, the elevator intellectualization control, each kind of alarm system, constitutes two cascade control systems with the computer networking and so on.(3).In domestic electric appliances applicationMay say like this that, the present domestic electric appliances basically have all used singlechip control, praised, the washer, the electric refrigerator, the air conditioner, the color television, other acoustic video frequency equipments from the electricity food, again to the electronic weighting equipment, all kinds of, omnipresent.(4).In computer network and correspondence domain applicationOf the modern singlechip has the correspondence connection generally, may very conveniently and the computer carries on the data communication,for provided the extremely good physical conditions application in between the computer network and the communication facility, the present communication facility basically has all realized singlechip intelligence control, from the handset, the telephone, the small program controlled switch, the building automatic correspondence ringing system, the train wireless correspondence, again the mobile phone which everywhere to the routine work in, the colony mobile communication, radio intercom and so on.(5).Singlechip in medical equipment domain applicationSinglechip quite is also widespread inmedical equipment use, for example medical life-support machine, each kind of analyzer, , ultrasound diagnosis equipment and hospital bed ringing system and so on. In addition, singlechip in the industry and commerce, the finance, the scientific research, the education, domain and so on national defense aerospaceall has the extremely widespread use.4.Singlechip development tendencyNow may say singlechip was all flowers blooms together, the time which hundred school of thought contended, in the world each big chip manufacture company has all promoted own singlechip, from 8, 16 to 32, innumerable, had everything expected to find, has compatibly with the mainstream C51 series, also had not not compatibly, but they unique, became mutually supplementarily, provided the broad world for singlechip application. Looks over singlechip developing process, may indicate singlechip development tendency, has approximately:(1). Low power loss CMOSThe MCS-51 series 8,031 promotes when the power loss reaches 630mW, but the present singlechip all about 100mW, along with more and more is generally low to singlechip power loss request, the present each singlechip manufacturer basic has all used CMOS (complementary metal oxide semiconductor craft). Looked like80C51 to use HMOS (namely high density metal oxide compound semiconductor craft) and CHMOS (supplementary high density metal oxide compound semiconductor craft). CMOS although power loss low, but because its physical characteristic decides its working speed insufficiently high, but CHMOS then had has been high speed and the low power loss characteristic, these characteristics, suited in are requesting the low power loss likely battery power supply the application situation. Therefore this kind of craft will be the main way which the next section of times singlechip will develop.(2). Miniature monolithicNow the conventional singlechip all is generally the central processor (CPU), the random access data storage (RAM), the read-only program memory (ROM), parallel and the serial communication connection, the interruption system, the timing circuit, the clock electric circuit integration on together the sole chip, the enlargement mode singlechip integrated like A/The D switch, PMW (pulse-duration modulation electric circuit), WDT (watch-dog), some singlechips (liquid crystal) actuate LCD the electric circuit all to integrate on the sole chip, such singlechip contains unit electric circuit more, the function is more formidable. Even singlechip merchant also may act according to the user requiremnet the body custom make, makes has oneself characteristic singlechip chip. In addition, present product universal demand volume small, weight light, this requests singlechip strong and the power loss is low besides the function, but also requests its volume to have to be small. Present many singlechips all have the many kinds of seals form, SMD (superficial seal) more and more receives welcome, to enable the system which constitutes by singlechip towards themicrominiaturized direction to develop.(3).Mainstream and multi- varieties coexistenceNow although singlechip variety is many, unique, but still as the core singlechip occupies the mainstream take 80C51, the compatible its structure and the command system have PHILIPS Corporation the product, the ATMEL Corporation's product and the Chinese Taiwan's Winbond series singlechip. Therefore C8051 was the core singlechip occupied the half of the country. But Microchip Corporation's PIC simplified the set of instructions (RISC) also to have the strong development tendency, the Chinese Taiwan's HOLTEK Corporation recent years singlechip output grows day by day, if the low price nature superior superiority, occupied a certain market minute volume. In addition also has MOTOROLA Corporation the product, the Japaneseseveral big companies' special-purpose singlechips. In the certain time, this kind of situation will be able to continue, will not have the monopoly aspect which some singlechip unified, will walk will be depends on for existence supplementarily, will complement one another, the communal development path.中文翻译单片机1. 单片机介绍单片机是一种集成电路芯片，应用超大规模技术把具有数据处理能力(如算术运算，逻辑运算、数据传送、中断处理)的微处理器(CPU)，随机存取数据存储器(RAM)，只读程序存储器(ROM)，输入输出电路(I/O口)，可能还包括定时计数器，串行通信口(SCI)，显示驱动电路(LCD 或 LED 驱动电路)，脉宽调制电路(PWM)，模拟多路转换器A/D 转换器等电路集成到一块单块芯片上,构成一个最小然而完善的计算机系统。

中文翻译可编程控制器从一个简单的遗产,这显著的系统已经进化到不仅取代机电设备,而是为了解决日益增加的一系列控制问题在这两种过程和非过程控制行业。

通过所有的适应情况,这些微处理器将继续作用到动力的新局面,20世纪90年代的自动化的工厂。

历史在20世纪60年代,机电设备的议事日程的屁股远为控制问题越来越受到关注。

这些设备,俗称继电器、正被利用着成千上万的制造过程和控制多个电机和永动机。

许多这些继电器被应用在交通行业,更确切的说,汽车工业。

这些继电器使用他们数以百计的电线和连接到调用控制解决方案。

接力的性能基本可靠——至少是一个单一的装置。

但是共同申请继电器板呼吁300 - 500或更多的继电器、可靠性及维护和支持这些电池板相关的问题变得非常巨大的挑战。

成本成为了另一个问题,尽管的低成本的圣火传递本身,面板安装成本可能会相当高。

总成本包括采购部件、配线和安装的劳动力,可以范围从$ 30 ~ 50美元的传递。

更糟的是,不断转变的需要,这个过程称为为复发性修改中的一个控制面板。

用继电器,这是一个昂贵的前景所完成的,因为它是一个主要的电路重组的努力,在面板。

除了这些改变是有时差,导致second-shift 记录维护噩梦月之后。

由此可知,这不是希有报废整个控制面板赞成一种新的以适当的部件装上了一个方式适合于新工艺。

如果再加上不可预知的,潜在的高成本、维持这些系统在大批量汽车生产线,显然,是有什么东西需要,提高了控制的过程——使它更可靠、更容易解决,并更加适应变化控制的需要。

这东西,在60年代末期,是第一个可编程控制器。

这第一次的革命的系统广域网路发展为一个特定的反应的需要大汽车制造商在美国。

这些早期的控制器,或可编程逻辑控制器(PLC)为代表的第一个系统,1可以用在我的工厂里,2个可能有“逻辑电路重组的改变或组件没有广泛的变化,并对3例诊断和修理时容易出现的问题。

有趣的是,要观察的进展,已经在过去的15年的可编程控制器的区域。