1、本科毕业设计(外文翻译)题 目 基于单片机的GPS定位 系统设计 姓 名 专 业 学 号 指导教师 信息工程学院二一五年三月基于单片机的GPS定位系统设计外文翻译摘 要本文介绍了一项利用单片机采集和处理GPS定位信息的设计,实现全球定位功能。该系统以ATMEL公司的AT89C51单片机为核心控制器件,通过串行口与GPS模块C3-370B通信,接收GPS模块输出的时间和定位信息,该输出信息格式采用NMEA-0183标准格式中的GPRMC语句。单片机接收到定位信息和时间信息后,将GPS模块输出的时间信息进行时差调整,再将所获取的位置和时间信息通过显示终端显示。经过调试后,本系统可以接收GPS定位信
2、息和时间信息,并把经度、纬度和时间通过屏幕显示出来。该系统主要由GPS模块、看门狗EEPROM模块、液晶显示模块及键盘组成,采用以AT89C51来控制各模块的设计思想。本文对每个模块逐一进行了研究,全面详细地论述了硬件电路的设计,对本设计中各模块的工作原理及功能进行了详细的论述。 关键词:GPS定位系统;单片机;液晶显示屏1总体设计在GPS系统的硬件设计中采用AT89C51单片机作为微处理器,AT89C51是美国ATMEL公司生产的低电压、高性能CMOS8位单片机,片内4K bytes可反复擦写的Flash只读程序存储器(ROM)和128 bytes的随机存取存储器(RAM),器件采用ATME
3、L公司的高密度、非易失性存储技术生产,兼容标准MSC-51指令系统,片内置通用八位中央处理器(CPU)和Flash存储单元7。 (1) 键盘模块本设计采用的是44的矩阵式键盘,直接与AT89C51的I/O口进行连接。利用键盘实现数据信息选择性输出的控制。(2) 液晶显示模块液晶显示模块要实现的功能是显示由单片机输出的定位信息,包括经度、纬度、高度的三维坐标及时间等。可由单片机选择性的显示某一个数据或同时显示几个数据。(3) GPS模块GPS模块是整个设计中最重要的核心模块,该模块的功能是把内部接受到的定位数据通过串行通信的方式传递给单片机,由单片机进而对这些数据进行相应的控制和处理。2 显示电
4、路设计51系列单片机与液晶模块的接口方式有两种,一种为直接访问方式,一种为间接控制方式。直接访问方式就是将液晶显示模块作为存储器或IO设备对待,直接挂在单片机总线上,单片机以访问存储器或IO设备的方式操作液晶显示模块。间接控制方式是单片机通过软件模拟液晶工作时序的方法实现与液晶显示模块的连接。 显示器的DB0-DB7引脚与单片机的P1口的8个I/O口串行连接,进行数据的传输;RS引脚接单片机的P2.0,过其高、电平选择显示数据或指令数据;RW、EN引脚接单片机的P2.1、P2.2,两引脚同时高电平完成对数据的读取,两引脚同时跌落至低电平数据被写入指令寄存器或数据寄存器(IR、DR);CS1、C
5、S2引脚接单片机的P2.3、P2.4,选择芯片左、右半屏信号;RST引脚接单片机的P2.5,可通过单片机对其发送复位信号;VLCD、VEE引脚分别为LCD的驱动电压和驱动负电压,两者用一个10K的滑动变阻器连接并一端接地,同时满足两引脚的电压要求;LED+、LED-引脚为LED背光板电源,其中正引脚接电源,负引脚通过一个三极管9012和一个1K电阻接到单片机的P2.6口12。由该模块构成的液晶显示方案与同类型的图形点阵液晶显示模块相比,不仅硬件电路结构简洁,且该模块的价格也略低于相同点阵的图形液晶显示模块。而且该模块低功耗、体积小、接口方式灵活、操作简单,满足本设计的要求,因此采用12864液
6、晶显示器是一个较好的解决方案。3 GPS模块设计GPS模块是整个电路设计的核心,直接决定了传输到单片机上的定位信息的相关要求,以及定位速度等性能水平。本设计采用的是JCOM C3-370B GPS接收模块。C3-370B是一款韩国JCOM出产的内置天线GPS接收模块,其定位快速,低耗电,搜星质量上乘,在众多GPS接收机中工作稳定、性能较为出众,它的输出、输入信息具有格式清晰、信息量大、数据结构完整等优点,非常适合于二次开发13。 各引脚功能如下:(1) EN:校准器使能端,上电或低电压时启用,2.0VVCC时禁用;(2) VCC:提供电压5.0V;(3) TXA:串行输出端口;(4) RXA:
7、串行输入端口;(5) GND:接地;(6) BOOT:模块启动端口,VCC复位时模块启动进入特殊调试模式。单片机AT89C51串口TXD、RXD分别与C3-370B的RXA、TXA进行连接,用于对C3-370B进行设置后,采集C3-370B的GPS定位和时间信息14。EN引脚为校准器使能端,接单片机的P3.6,通过其选用校准器(上电或低电压时启用,在2.0V到VCC之间禁用)。BOOT引脚为模块启动端口,与单片机的P3.7相连,VCC复位时模块启动进入特殊调试模式。4系统电源设计本系统中各模块所用芯片的工作电压如表3所示。由于本系统中所有芯片的工作电压都维持在5V左右,所以可以采用+5V的直流
8、电源来供电。 模块单片机看门狗及EEPROMGPS液晶显示模块芯片AT89C51X5045C3-370B12864工作电压(V)5.02.7-5.53.6-5.53.0-5.5为了确保系统电路的安全可靠,应提供稳定的电源电压,可考虑增加DC/DC转换器,这里设计了一个简单的LM7805稳压电路,是最常用的线性降压型DC/DC转换器。LM7805是常见的三端稳压集成电路78系列的一种,用78系列三端稳压IC来组成稳压电源所需的外围元件极少,电路内部还有过流、过热及调整管的保护电路,使用起来可靠、方便,而且价格便宜。该系列集成稳压IC型号中的78后面的数字代表该三端集成稳压电路的输出电压,由此可见
9、LM7805的输出电压恰好为5V,刚好是51系列单片机运行所需的电压11。LM7805作为三端稳压集成电路,显而易见,它有三个引脚,分别是输入端、接地端和输出端,TO-220的标准封装。当输出电流较大时,应配上散热板和接地脚相连,当稳压管温度过高时,稳压性能将变差,甚至损坏。参考文献1 HONG Huanfeng,LI Chuanwei.Adhibition of electrical isolationin electrical controlling circuitsJ.Machine Building & Automa-tion,2007,36(2):134 - 136.2 QIU Yu
10、chun,LI Wenjun. Infrared communication interface inmicrocontroller systemJ. Electronic & Computer Design World,2000(5):36 - 37.3 FANG Jianchao.Design and realization of infrared communica-tion among microcomputersJ. Computer Technology and Auto-mation,2001,20(2):57 - 61.4 Liyuan, Hu Xiulin. Based on
11、 GPS-OEM board and chip positioning terminal development J. Hubei: Hubei posts and telecommunications technology, 2004, 29 32.5NMEAProtocolSpecification.Verison1.31.FastraxOy.2003.066 ElliottD.Kaplan.UnderstandingGPSPrinciplesM. Beijing: Electronics Industry Press,2002.7AnnaM.Murph,ShinichiTsutsumi,
12、PererGaussen.Low-Power,Low-CostBipolrGPSReceierChipJ,IEEEJOURNALOFSOLID-STATECIRCUITS.1997,4(4):587-591.8 Jia Jinling. The design and guidance of Microcomputer Principle and interface technology course M. Chongqing: Chongqing University press, 2001.12Foreign Language Translation Microcontroller-Base
13、d Design GPS Positioning SystemAbstractThis article describes the use of a single-chip GPS positioning information acquisition and processing design, global positioning. The system ATMEL Corporation AT89C51 microcontroller as the core control device, through a serial port to communicate with the GPS
14、 module C3-370B, receiving time and positioning information GPS module output, the output format using the NMEA-0183 standard format GPRMC statement. After the microcontroller receives positioning information and time information, time information output by the GPS module to adjust the time differen
15、ce, then the acquired position and time information displayed by the display terminal. After commissioning, the system can receive GPS positioning information and time information, and the latitude, longitude and time displayed on screen.The system consists of GPS module, watchdog EEPROM module, LCD
16、 module and keyboard components, the use to AT89C51 to control each module design. In this paper, one by one for each module studied comprehensively discussed in detail the hardware design, working principle and function of the design of the modules were discussed in detail.Keywords: GPS positioning
17、 system; microcontroller;P LCD display1 Overall DesignAT89C51 microcontroller hardware design using the GPS system as a microprocessor, AT89C51 ATMEL produced by the US low-voltage, high-performance CMOS8 bit microcontroller, on-chip 4K bytes of Flash rewritable read-only program memory (ROM) and 12
18、8 bytes of random access memory (RAM), the device uses ATMELs high density nonvolatile memory technology production, compatible with standard MSC-51 instruction set, the eight-chip, general-purpose central processing unit (CPU) and a Flash memory cell 7.Peripheral circuits from the keyboard, a watch
19、dog and EEPROM module, LCD module, GPS module(1) keyboard moduleThis design uses a 4 4 matrix keyboard directly with AT89C51 the I / O port for connection. Using the keyboard for control data selectively output.(2) liquid crystal display moduleLCD module to achieve the function is to display the loc
20、ation information from the microcontroller output, including longitude, latitude, altitude and other three-dimensional coordinates and time. SCM can optionally display one or both data display several data.(3) GPS moduleGPS module is the whole design of the most important core module, function of th
21、e module is to receive an internal positioning data to the microcontroller through serial communication, and then the data corresponding to the control and processing by the microcontroller.2 Shows The Circuit DesignInterface 51 series of LCD module, there are two, one for direct access method, an i
22、ndirect control. Direct access method is to LCD module as a memory or I / O devices to treat, directly linked to the microcontroller bus, the microcontroller to access memory or I / O devices manipulate LCD module. Indirect control is a single chip analog LCD timing work through software implementat
23、ion and LCD connected to the module.8 I monitor DB0-DB7 pin microcontroller P1 port / O port serial connection for data transmission; RS pin is connected to the MCU P2.0, through its high level select display data or instruction data ; RW, EN pin is connected to the MCU P2.1, P2.2, two pins at the s
24、ame time high reading of the data is completed, the two pins simultaneously dropped to the low level data is written to the instruction register or data register ( IR, DR); CS1, CS2 pin is connected to the MCU P2.3, P2.4, select chip left, right panel signal; RST pin is connected to the MCU P2.5, ca
25、n send its signal through the MCU reset; VLCD , VEE pins are the LCD drive voltage and drive negative voltage, both sliding rheostat a 10K connection and end of the ground, while meeting the requirements of both voltage pin; LED +, LED- pin LED backlight power supply, which Positive pin is connected
26、 to the power supply, the negative pin through a transistor 9012 and a 1K resistor to the microcontroller ports P2.6 12.Liquid crystal display constituted by the module program with the same type of dot matrix LCD module compared to not only the hardware circuit structure is simple, the price and th
27、e module is also slightly lower than the same graphic dot matrix LCD module. And the module low power consumption, small size, flexible interface mode, simple operation, to meet the requirements of the design, so a 12864 LCD display is a better solution3 GPS Module DesignGPS module is the core of th
28、e circuit design directly determines the location information is transmitted to the relevant requirements on the microcontroller, positioning speed and performance levels. This design uses a JCOM C3-370B GPS receiver module.C3-370B JCOM produced in Korea is a built-in antenna GPS receiver module pos
29、itioning fast, high power consumption, search star quality, stable and in many GPS receivers, the performance is more superior, its output, input information has a format clear, informative, complete data structure, etc., is very suitable for secondary development 13.Pin function as follows:(1) EN:
30、calibration enable end, when the power or low voltage is enabled, 2.0V-VCC is disabled;(2) VCC: providing a voltage 5.0V;(3) TXA: serial output port;(4) RXA: serial input port;(5) GND: Ground;(6) BOOT: module start port, VCC reset module boot into a special debug mode.SCM AT89C51 serial TXD, RXD res
31、pectively C3-370B of RXA, TXA connection, after C3-370B set for C3-370B acquisition of GPS location and time information 14. EN pin is calibrated enable end, then the MCU P3.6, through its selection of the calibrator (on power or low voltage enable, disable, in between 2.0V to VCC). BOOT pin module
32、start port, and P3.7 microcontroller connected, VCC reset module boot into a special debug mode. Hardware connection diagram shown in Figure 7.4 System Power Supply DesignThe chips used in the modules of the operating voltage as shown in Table 3. Because of this system, all the chips operating volta
33、ge is maintained at about 5V, so you can use the + 5V DC power supply to power.ModuleSCMWatchdog and EEPROMGPSLCD moduleChipAT89C51X5045C3-370B12864Operating voltage (V)5.02.7-5.53.6-5.53.0-5.5To ensure safe and reliable system circuit, should provide a stable power supply voltage, may consider incr
34、easing the DC / DC converter, where the design of a simple LM7805 voltage regulator circuit, is the most common linear step-down DC / DC converter.LM7805 is a common three-terminal regulator IC 78 series A, with 78 series three-terminal regulator IC to form the external components required for minim
35、al power supply, internal circuit as well as overcurrent, overheating protection and adjustment pipe circuit, use, reliable, convenient, and cheap. The family of integrated voltage regulator IC Part 78 behind the figures represent the three-terminal integrated voltage regulator circuit output voltag
36、e, output voltage shows LM7805 is exactly 5V, just the 51 series MCU operating voltage required 11.LM7805 as a three-terminal regulator IC, it is obvious that it has three pins, which are input and output ground, TO-220 standard package. When the output current is large, it should be coupled with th
37、e heat radiating plate and ground pin is connected to the regulator when the temperature is too high, the regulator will be poor, or even damaged.REFERENCES 1 Zhang Yigang, et al. MCS-51 application design M. Harbin: Harbin Institute of Technologypress,20042 Mei Lifeng, Wang Yanqiu. Microcomputer pr
38、inciple and interface technologyM.BeijingTsinghua UniversityPress, 20043 Jian Hua Shi. Beijing microcontroller technology principle and application M.Beijing University of Posts and Telecommunications Press, 2008.4 Liyuan, Hu Xiulin. Based on GPS-OEM board and chip positioning terminal development J
39、. Hubei: Hubei posts and telecommunications technology, 2004, 29 32.5NMEAProtocolSpecification.Verison1.31.FastraxOy.2003.066 ElliottD.Kaplan.UnderstandingGPSPrinciplesJ. Beijing: Electronics Industry Press,2002.7AnnaM.Murph,ShinichiTsutsumi,PererGaussen.Low-Power,Low-CostBipolrGPSReceierChipJ,IEEEJOURNALOFSOLID-STATECIRCUITS.1997,4(4):587-591.8 Jia Jinling. The design and guidance of Microcomputer Principle and interface technology course M. Chongqing: Chongqing University press, 2001.12