基于单片机的红外遥控电子密码锁的外文及翻译.docx

1、基于单片机的红外遥控电子密码锁的外文及翻译毕业设计(论文)外文资料翻译 学生姓名： 朱德涛 学 号： *所在学院： 电子与信息工程学院 专 业： 电子信息工程 * * 2014年 03 月 15 日Proceedings of 2009 4th International Conference on Computer Science & EducationThe Design of Electronic Locks Based on Infrared Remote-Control with MCUZhangCheng Xue ShunXiang WuDepartment of Automati

2、on Department of AutomationXiamen University Xiamen UniversityXiamen, China Xiamen, China * wsx1* Abstract-At present, key-pad electronic lock with alarmingfuntion is to gradually replace the traditional mechanicallocks,overcoming the shortcomings of the traditional mechanicallocks which contain few

3、 password and lack of reliabiIty, but keypadelectronic lock makes a great progress in terms of technologyand performance.This paper represents a type of remote-controlledelectronic lock developed with the chip of AT89S51.This type of lock have two input devices,one of them is a 4*3matrix keyboard mo

4、unted on the lock,the other one is a remotecontroller which also have 4*3 matix keyboard.we can use eitherof them to open the lock or change the password we have set. Inthe design,we adopt the infrared ray as the medium,because ofthe strong anti-interference ability, reliable transmission ofinformat

5、ion. Index Terms-MCU Electronic locks Infrared Remote-control LCD1602 I.INTRODUCTION The design is based on single chip,makes use of 4 * 3keyboard and infrared remote controller as input,LCD1602could display the information of the steps when you areoperating.This designment could also realize modify

6、ing thepassword and alarming. When a requirement to reset thepassword,it is necessary to make sure the password iscorrect,otherwise it will make noise to warn you the passwordis wrong.In this designment,1 limit the length of the passwordat six,Just like the ATM of bank.you must enter right passwordi

7、f you want to get through.II. THE FRAMEWORK OF THE DESIGNMENT The designment consists of six modules: the maincontroller module, LCD1602 module, 4*3 keyboard module,infrared remote control module, the alarm module, theunlocking simulation module. Main Controller Module: a low-power, high-performance

8、CMOS 8-bit single chip, the device used ATMELs highdensity,non-volatile memory technology, compatible withstandard command system of MCS-51.An 8-bit commoncentral processing unit and ISP Flash memory cell areintegrated in this chip. LCD modules: LCD1602 is a character liquid crystaldisplay modules,

9、is a type of dot-matrix LCD dedicating todisplay letters, numbers, symbols and so on.Consideringeconomy and practice in this regard,adopting LCDl602 isenough to meet the requirements of character displaying on the LCD. 4*3 keyboard module: Because of I/O port of MCU islimited, according to matrix ke

10、yboard to realize circuit.In thisway,we can design enough buttons on the keyboard but nottake up too many ports of the MCU. Infrared remote control module: the design used a universalTV remote controller as input device,the device can provide awide range of infrared encoding format, so we make use o

11、f thecoding format of the pulse width modulation. Alarm modules: In this design, select the buzzer to sound awarning. The single-chip through the port P3.2 outputs a squarewave pulse-driven audio loudspeakers. Unlocking instructions: In this design,1 choose to use LEDlights to simulate the situation

12、 of the lock.when we enterpassword,LED lights will flash on behalf of the unlocking issuccessful. Figure 1.The framework of the designment A.The design of Matrix keyboard Matrix keyboard working principle: vertical lines throughthe resistance connected +5V power.when no keys are presseddown,the vert

13、ical lines is in high level situation,otherwise ,thesituation is the same with the horizontal lines which is crossedon the button.Originally ,the horizonal lines are in low-level,when we check the varying situation of the vertical Iines,thatmeans button is pressed down,at this time we save the situa

14、tionof port p2.4-p2.6,then we program to make the port p2.0-p2.3in high level situation line by line,at the meantime checking thevarying of the situation of the port p2.4-p2.6,when itchanges,we save the situation of the port p2.0-p2.3.In thisway,we have known which button had been pressdown,because

15、we have recorded situation of the portp2.0p2.6.Different keys have different coding format, thekeyboard processing tasks are:Firstly, to determine whether ornot press the button,then check which button havepressed,through the programming,get the formation of keycoding.All of the key code shown in th

16、e following table: TABLE 1. THE VALUE OF KEY CODING EE DE BE ED DD BD EB DB BB E7 D7 B7 Figure 2. The 4 3 keyboard circuitB.The design of infrared remote control1)The introduction of the LC7461 At present,there are lots of chips dedicating to transmit theinfrared ray, in terms of the encoding format

17、 that can bedivided into two major categories: PWM and PPM. Here wehave adopted a relatively easy to modulate,the PWMs, LC7461chip. When the infrared controllerbutton is pressed,it will sendout some signal which contains the information about thecoding format.The signal has the following characteris

18、tics: thePWM pulse width last for 0.56ms, interval 0.56ms as a periodof 1.12ms representing the binary 0; the PWM pulse widthlast for 0.56ms,interval 1.68 ms as a period of 2.24msrepresenting the binary 1 .The above-mentioned 0 and 1composed of 42 bits binary code, as contained in the 38kHzfrequency

19、 modulation for the second launch in order toenhance efficiency and reduce lower power consumption, andthen through the infrared diode to send out. “0” “1” 0.56 ms 0.56ms 1.125ms 2.25ms Figure 3. The formation of the signal.2)The infrared receiversInfrared receiver is an integrated circuit including

20、 a set offuntions of receiving,amplification and shaping, without anyexternal components,takes all the work compatible with TTLlevel,it is suitable for a variety of infrared remote control andinfrared signal transferring.Infrared receiver transmits thedemodulated signal to the single-chip AT89S51 by

21、 the way ofinterruption. NOTE: When there is no infrared signal,the outputport is in high-level,so the signal we received is contrary to thesignal sent out before.3)The decoding of the infrared signal When we receive a signal containing a synchronizedbeginning of 9ms low-level and 4.5ms high-Level,i

22、t makes usprepare to decode the data.The key of decoding is how toidentify 0 and 1. According to the formation of the signalwe can find that the definition of 0 and 1 starts with 0.56mslow-level, the only difference between them is the width of thehigh-level, 0 bit is 0.56 ms, 1 bit is 1.68 ms,so we

23、 delay0.9ms to compare the current level for identifying the bit,theflow chart as follows: N Y N YFigure 4. The flow chart of decoding4)The working process of the infrared remote-conroller IR transmit / receive control circuits are achievedby the AT89S51microcontroller with simple circuit,selectable

24、 output control method and very practical The specific work process is as follows: Launch: First, sent back the data from the serialtransmit port P3.1 to the P1.1 port for internalmodem, sent out from the P1.2 port, and then firedout through the infrared emitting diodes, firingdistance is about 10m.

25、 Receipt: The infrared receiver head matched withthe launch is used. , sent out the data launched to theserial port 3.0, and then the system will confirmwhether the send data are consistent with the receivedata, yes will unlock, no will give up.C.The design of main circuit According to the design of

26、 the analysis, the hardwarecircuitry of single-chip electronic locks as shown in the Figurebelow. P0port connect LCDl602 8-bit data bus,at the sametime, P0port is connected to the 8-bit ports of anode-sharingdigital tube,the port of P0.1strobes LED. P2 port access 4 * 3 matrix keyboard circuit, whil

27、e P2.5, P2.6 and P2.7 respectivelyconnect the RS, RW, E-port of the LCD1602. Buzzer alarmprompted by the P3.2 output. Figure 5. The design of main circuitIII. RESULT Accrding to the design ,the operation is shown as thefigures below: Figure 6. a unlocking interface When we want to reset the password

28、,firstly,the systemchecks out the password is correct or not,if the password isright,we could get in the next step,otherwise the system makeswarning. Figure 7. Interface of checking the password Figure 8. Interface of reset passwordIV. COCLUSION In this paper, an infrared remote control electroniclo

29、cks was designed and implemented, the maintechnical indicators are: the lock opening, passwordstorage, the effective protection of users password,auto-alarm if the wrong password, unlock thekeyboard of the machine, remote unlocking and otherfunctions. Because of infrared remote control used inthis l

30、ock system, there are many advantages:Infrared launching device use infrared light-emittingdiodes miniature remote control transmitter is easy and inexpensive; use digital signal coded modulation to improve anti-interferencewhen signal are transmitted, less misoperation , low power consumpti-on, inc

31、luding other advantages, such as fast response infrared transmission, high transmission efficiency, stable and reliableoperation .Based on these advantages, this lock canbe widely used in civil doors and warehouse doors. In the information age,in my opinion,the design could playan important part in our daily life and will supplant thetranditon traditional mechanical lock later on.Though there issome points