1、GPS模块使用手册GPS模块使用手册一、GPS模块的几个重要指标1.卫星轨迹全球有24颗GPS卫星沿6条轨道绕地球运行(每4个一组),GPS接收模块就是靠接收这些卫星来进行定位的。但一般在地球的同一边不会超过12颗卫星,所以一般选择可以跟踪12颗卫星以下的器件就可以了。当然,所能跟踪的卫星数越多,性能越好。大多数GPS接收器可以追踪812颗卫星。计算2维坐标至少需要3颗卫星,4颗卫星可以计算3维坐标。2.并行通道由于最多可能有12颗卫星是可见的,GPS接收器必须按顺序访问每一颗卫星来获取每颗卫星的信息,所以市面上的GPS接收器大多数是12并行通道型的,这允许它们连续追踪每一颗卫星的信息。12通
2、道接收器的优点包括快速冷启动和初始化卫星的信息,而且在森林地区可以有更好的接收效果。一般12通道接收器不需要外置天线,除非是在封闭的空间,如船舱或车厢中。3.定位时间定位时间是指重启GPS接收器时,确定现在位置所需的时间。对于12通道接收器,冷启动时的定位时间一般为35 min,热启动时为1530 s。4.定位精度普通GPS接收器的水平位置定位精度在510 m内。5.DGPS功能DGPS是一个固定的GPS接收器,用于接收卫星的信号。DGPS可以准确地计算出理论上卫星信号传送到的精确时间,然后将它与实际传送时间相比较,并计算出差值。DGPS将这个差值发送出去,其它GPS接收器就可以利用这个差值得
3、到一个更精确的位置读数(510 m或者更少的误差)。许多GPS设备提供商在一些地区设置了DGPS发送机,供客户免费使用,只要客户所购买的GPS接收器有DGPS功能即可。6.信号干扰要获得一个很好的定位信号,GPS接收器必须至少能接收到35颗卫星。如果是在峡谷中或两边高楼林立的街道上,或者是在茂密的丛林里,有可能接收不到足够的卫星,无法定位或者只能得到二维坐标。同样,如果在一个建筑里面,有可能无法更新位置。一些GPS接收器有单独的天线可以贴在挡风玻璃上,或者将一个外置天线放在车顶上,这有助于接收器收到更多的卫星信号。二、HOLUX M-89 GPS模块特性我们选用的是台湾生产的HOLUX M-8
4、9 GPS模块,并为其配备了PCB板,以方便与单片机进行连接,下面与反面如下图所示, HOLUX M-89 GPS接收卫星信号时一般还需要配备天线,如下图所示:HOLUX M-89 GPS模块主要特性如下:产品特征通 道:并行32通道频 率:L1 1575.42MHzC/A码(1.023MHZ码片速率)跟踪灵敏度:-159dB动态性能速 度:515米/秒加速度:4g颠 簸:20米/秒捕获时间重获取时间:0.1秒热启动时间:1秒温启动时间:33秒冷启动时间:36秒精度定位: 10米(2D RMS) 1-5米 (DGPS)速度: 0.1米/秒时间: 1ms数据特性I/O信息:1个全双工串行TTL接
5、口数据传输速率: 480038400 (标准:9600)格式: SiRF二进制和NMEA-0183(v3.01)GGA,GLL,GSA,GSV,RMC,VTGDGPS协议:RTCM SC-104,类型1,2和9脉冲延时: 100ms电气特性输入电压: 3.35VDC后备电源: 直流3V输入电流: 80mA物理特性尺寸: 25.4mm(D)25.4mm(W)3mm(H)重量: 7g环境特性操作温度: -30+85存贮范围: -40+85三、12864显示GPS数据实验1.HOLUX M-89 GPS模块与DD-900实验开发板的连接HOLUX M-89 GPS模块安装在一块PCB板上,板上引出有
6、6针间距为2.54mm的插针,可方便地与顶顶电子开发的DD-900实验开发板进行连接,各插针管脚功能及其与DD-900实验开发板的连接方法如下:1脚:指示灯,通电常亮,接收到卫星开始闪烁,模块板上带有LED灯,实验时可不接。2脚:外部复位输入,模块内部有复位电路,实验时可不接。3脚:模块串口数据输出。接DD-900实验开发板MCU的RXD脚(P30脚)。4脚:模块串口数据输入。接DD-900实验开发板MCU的TXD脚(P31脚)。5脚:GND。接DD-900实验开发板的地端。6脚:电源输入,电压范围:3.3-5V,接DD-900实验开发板的3.3V或5V端。2.GPS源程序实验步骤(1)打开S
7、TC下载软件,将“12864液晶屏显示GPS数据C51源程序”中的“GPS_12864.hex”目标文件下载到DD-900实验开发板上。(2)取一只12864液晶显示屏,将其插到DD-900实验开发板上。(3)将GPS模块与天线连接好。(4)找四根杜邦线,将GPS模块与DD-900实验开发板的连接好。断开232与单片机的短接插针。使单片机只能与GPS模块进行通信。(5)打开DD-900实验开发板电源,约几十秒后,在12864液晶屏上即可显示出经度、纬度、时间、海拔高度等信息,如下图所示:以上信息的意思为:东经120度23.7285分,北纬36度17.3538分,时间为15点10分52秒,海拔高
8、度为145.6米。需要注意的是,实验时,要将GPS模块和天线放置在室外,以便接收到卫星信号,另外,GPS启动时需要一定的启动时间,GPS启动后才能接收到并计算出正确的数据。另外,如果你没有采用DD-900实验开发板,而是采用其它实验板,需要将单片机晶振频率设置为11.0592MHz,以保证GPS模块与单片机按照9600的波特率进行通信。四、用串口调试助手查看GPS数据1.GPS模块与DD-900的连接(1)GPS模块通过DD-900实验开发板串口,可以方便地与PC机进行连接,连接方法如下:(2)GPS模块的3脚(模块串口数据输出)接DD-900实验开发板MCU的TXD脚(P31脚),注意,与上
9、个实验不同。(3)GPS模块的4脚(模块串口数据输入)接DD-900实验开发板MCU的RXD脚(P30脚),注意,与上个实验不同。(4)GPS模块5脚(GND)接DD-900实验开发板的地端。(5)GPS模块6脚(电源输入)接DD-900实验开发板的3.3V或5V端。(6)取下DD-900的MCU。2.实验方法 连接完成后,打开顶顶串口调试助手,选择好串口(一般为串口1,如果采用USB转串口,要选择虚拟串口号,本例采用的是USB转串口,虚拟串口号为COM5)。波特率选择为9600,校验位为NINE,数据位为8,停止位为1。以上设置完成后,打开串口,即可在接收窗口中接收到有关的GPS数据,如图所
10、示:五、其它1.GPS模块与PC机的通信模组可以直接采用电平转换电路MAX232,将GPS模块的串口和PC机的串口连接,用串口调试工具和GPS模块调试软件监控模块输出的数据,注意:模块的默认波特率为9600,PC机串口波特率必须设置成9600。如果没有接GPS天线或收不到卫星信号。模组上的LED灯一直常亮,如果收到有效的卫星信号LED开始闪烁。2.GPS的数据协议GPS数据格式支持 NMEA0183 V 3.01 数据协议。格式 NMEA0183 V3.01: GPGGA(1 次1 秒)、GPGSA(1 次5 秒)、GPGSV(1 次5 秒)、GPRMC(1 次1 秒)、GPVTG(1 次1
11、秒)。下面是调试模组用串口监控到的数据:无卫星状态:$GPGGA,000355.026,8960.0000,N,00000.0000,E,0,0,137.0,M,13.0,M,*44$GPGSA,A,1,*1E$GPGSV,1,1,00*79$GPRMC,000355.026,V,8960.0000,N,00000.0000,E,0.00,0.00,060180,N*79$GPVTG,0.00,T,M,0.00,N,0.00,K,N*32$GPGGA,000356.026,8960.0000,N,00000.0000,E,0,0,137.0,M,13.0,M,*47$GPRMC,000356.
12、026,V,8960.0000,N,00000.0000,E,0.00,0.00,060180,N*7A$GPVTG,0.00,T,M,0.00,N,0.00,K,N*32$GPGGA,000357.026,8960.0000,N,00000.0000,E,0,0,137.0,M,13.0,M,*46$GPRMC,000357.026,V,8960.0000,N,00000.0000,E,0.00,0.00,060180,N*7B$GPVTG,0.00,T,M,0.00,N,0.00,K,N*32$GPGGA,000358.026,8960.0000,N,00000.0000,E,0,0,13
13、7.0,M,13.0,M,*49$GPRMC,000358.026,V,8960.0000,N,00000.0000,E,0.00,0.00,060180,N*74$GPVTG,0.00,T,M,0.00,N,0.00,K,N*32$GPGGA,000359.026,8960.0000,N,00000.0000,E,0,0,137.0,M,13.0,M,*48$GPRMC,000359.026,V,8960.0000,N,00000.0000,E,0.00,0.00,060180,N*75$GPVTG,0.00,T,M,0.00,N,0.00,K,N*32$GPGGA,000400.026,8
14、960.0000,N,00000.0000,E,0,0,137.0,M,13.0,M,*43$GPGSA,A,1,*1E$GPGSV,1,1,00*79$GPRMC,000400.026,V,8960.0000,N,00000.0000,E,0.00,0.00,060180,N*7E$GPVTG,0.00,T,M,0.00,N,0.00,K,N*32$GPGGA,000401.026,8960.0000,N,00000.0000,E,0,0,137.0,M,13.0,M,*42$GPRMC,000401.026,V,8960.0000,N,00000.0000,E,0.00,0.00,0601
15、80,N*7F$GPVTG,0.00,T,M,0.00,N,0.00,K,N*32$GPGGA,000402.026,8960.0000,N,00000.0000,E,0,0,137.0,M,13.0,M,*41$GPRMC,000402.026,V,8960.0000,N,00000.0000,E,0.00,0.00,060180,N*7C$GPVTG,0.00,T,M,0.00,N,0.00,K,N*32$GPGGA,000403.026,8960.0000,N,00000.0000,E,0,0,137.0,M,13.0,M,*40$GPRMC,000403.026,V,8960.0000
16、,N,00000.0000,E,0.00,0.00,060180,N*7D$GPVTG,0.00,T,M,0.00,N,0.00,K,N*32$GPGGA,000404.026,8960.0000,N,00000.0000,E,0,0,137.0,M,13.0,M,*47$GPRMC,000404.026,V,8960.0000,N,00000.0000,E,0.00,0.00,060180,N*7A$GPVTG,0.00,T,M,0.00,N,0.00,K,N*32$GPGGA,000405.026,8960.0000,N,00000.0000,E,0,0,137.0,M,13.0,M,*4
17、6$GPGSA,A,1,*1E有卫星状态:$GPGGA,090113.000,3958.2847,N,11616.6454,E,1,8,1.00,67.6,M,-6.7,M,*78$GPRMC,090113.000,A,3958.2847,N,11616.6454,E,0.00,0.00,080110,A*60$GPVTG,0.00,T,M,0.00,N,0.00,K,A*3D$GPGGA,090114.000,3958.2847,N,11616.6456,E,1,8,1.00,67.7,M,-6.7,M,*7C$GPRMC,090114.000,A,3958.2847,N,11616.645
18、6,E,0.00,0.00,080110,A*65$GPVTG,0.00,T,M,0.00,N,0.00,K,A*3D$GPGGA,090115.000,3958.2846,N,11616.6456,E,1,8,1.00,67.7,M,-6.7,M,*7C$GPRMC,090115.000,A,3958.2846,N,11616.6456,E,0.00,0.00,080110,A*65$GPVTG,0.00,T,M,0.00,N,0.00,K,A*3D$GPGGA,090116.000,3958.2846,N,11616.6456,E,1,8,1.00,67.8,M,-6.7,M,*70$GP
19、RMC,090116.000,A,3958.2846,N,11616.6456,E,0.00,0.00,080110,A*66$GPVTG,0.00,T,M,0.00,N,0.00,K,A*3D$GPGGA,090117.000,3958.2845,N,11616.6457,E,1,8,1.00,67.8,M,-6.7,M,*73$GPGSA,A,3,29,15,10,18,09,21,24,27,1.28,1.00,0.79*08$GPGSV,3,1,10,24,78,302,38,15,77,207,42,29,36,238,48,10,33,073,24*76$GPGSV,3,2,10,
20、21,29,310,39,08,22,054,18,15,276,42,27,14,167,36*7D$GPGSV,3,3,10,09,05,175,35,40,*45$GPRMC,090117.000,A,3958.2845,N,11616.6457,E,0.00,0.00,080110,A*65$GPVTG,0.00,T,M,0.00,N,0.00,K,A*3D$GPGGA,090118.000,3958.2846,N,11616.6457,E,1,8,1.00,67.8,M,-6.7,M,*7F$GPRMC,090118.000,A,3958.2846,N,11616.6457,E,0.
21、00,0.00,080110,A*69$GPVTG,0.00,T,M,0.00,N,0.00,K,A*3D$GPGGA,090119.000,3958.2846,N,11616.6458,E,1,9,0.85,67.8,M,-6.7,M,*7C$GPRMC,090119.000,A,3958.2846,N,11616.6458,E,0.00,0.00,080110,A*67$GPVTG,0.00,T,M,0.00,N,0.00,K,A*3D$GPGGA,090120.000,3958.2847,N,11616.6459,E,1,9,0.85,67.8,M,-6.7,M,*76$GPRMC,09
22、0120.000,A,3958.2847,N,11616.6459,E,0.00,0.00,080110,A*6D$GPVTG,0.00,T,M,0.00,N,0.00,K,A*3D$GPGGA,090121.000,3958.2847,N,11616.6460,E,1,9,0.85,67.8,M,-6.7,M,*7D$GPRMC,090121.000,A,3958.2847,N,11616.6460,E,0.00,0.00,080110,A*66$GPVTG,0.00,T,M,0.00,N,0.00,K,A*3D$GPGGA,090122.000,3958.2847,N,11616.6461
23、,E,1,9,0.85,67.8,M,-6.7,M,*7F$GPGSA,A,3,29,15,10,18,09,21,24,08,27,1.14,0.85,0.77*0D$GPGSV,3,1,10,24,78,302,38,15,77,207,42,29,36,238,48,10,33,073,22*70$GPGSV,3,2,10,21,29,310,39,08,22,054,21,18,15,276,42,27,14,167,36*7E$GPGSV,3,3,10,09,05,175,35,43,*46$GPRMC,090122.000,A,3958.2847,N,11616.6461,E,0.
24、00,0.00,080110,A*64$GPVTG,0.00,T,M,0.00,N,0.00,K,A*3D$GPGGA,090123.000,3958.2848,N,11616.6462,E,1,9,0.85,67.8,M,-6.7,M,*72$GPRMC,090123.000,A,3958.2848,N,11616.6462,E,0.00,0.00,080110,A*69$GPVTG,0.00,T,M,0.00,N,0.00,K,A*3D2.GPS 语句数据格式GPS模块可以输出多种数据格式输出语句,这样,在源程序中,我们通过对这些输出语句进行解析,就可以得到GPS的定位数据。下面重点介绍G
25、PRMC和GPGGA输出语句:(1)GPRMC输出语句其标准格式为:$GPRMC, ,A*hh 例如:$GPRMC,024813.640,A,3158.4608,N,11848.3737,E,10.05,324.27,150706,A*50 标准定位时间(UTC time)格式:时时分分秒秒.秒秒秒(hhmmss.sss)。 定位状态,A = 数据可用,V = 数据不可用。 纬度,格式:度度分分.分分分分(ddmm.mmmm)。 纬度区分,北半球(N)或南半球(S)。 经度,格式:度度分分.分分分分。 经度区分,东(E)半球或西(W)半球。 相对位移速度, 0.0 至 1851.8 knots
26、(节) 相对位移方向,000.0 至 359.9度。实际值。 日期,格式:日日月月年年(ddmmyy)。 磁偏角,(000 - 180)度,前导位数不足则补0 。 磁偏角方向,E=东W=西。A* 语句结束标志符。hh 从$开始的所有ASCII码校验和。 回车换行。(2)GPGGA输出语句 这是一帧GPS定位的主要数据,也是使用最广的数据。为了便于理解,下面举例说明GPGGA语句各部分的含义。其标准格式为:$GPGGA, ,M,M,*hh传送的信息说明如下:$GPGGA:起始引导符及语句格式说明(本句为GPS定位数据)。 UTC时间,时时分分秒秒格式。 纬度,度度分分.分分分分格式(第1位是0也
27、将传送)。 纬度半球,N或S(北纬或南纬)。 经度,度度度分分.分分分分格式(第1位0也将传送)。 经度半球,E或W(东经或西经)。 GPS质量指示,0:方位无法使用,1=非差分GPS获得方位,2=差分方式获得方位(DGPS),6=估计获得。 使用卫星数量,从00到12(第1位是0也将传送)。 水平精确度,0.599.9。 天线离海平面的高度,-9 999.99999.9m。M指单位米。 大地水准面高度,-999.99999.9m。M指单位米。 差分GPS数据期限(RTCM SC-104),最后设立RTCM传送的秒数量(例如无DGPS为0)。 差分参考基站标号,从00001023,实时DGPS
28、时无。* 语句结束标志符。hh 从$开始的所有ASCII码校验和。 回车换行。例如,假如实时收到的一条“$GPGGA”语句如下:$GPGGA,114641,3002.3232,N,12206.1157,E,1,03,12.9,53.2,M,11.6,M,*4A这是一条GPS定位数据信息语句,其含义是:UTC时间为11时46分41秒,位置在北纬30度2.323 2分,东经122度6.115 7分,普通GPS定位方式,接收到3颗卫星,水平精度为12.9 m,天线离海平面高度为53.2m,所在地离地平面高度为11.6m,校验和为4AH。由于GPS模块发送的不止是一条语句,要完整的接收这条“$GPGGA”语句,就必须判断这条语句的头。也就是“$GPGGA,”这7个字符,当完整的收到这7个字符后,才能保证是所需要的数据。
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