我是C ++的初学者，请保持友善，
我想读取gps传感器发送的数据。
我的代码现在看起来像这样：
#include <iostream>
#include <stdio.h> // standard input / output functions
#include <stdlib.h>
#include <string.h> // string function definitions
#include <unistd.h> // UNIX standard function definitions
#include <fcntl.h> // File control definitions
#include <errno.h> // Error number definitions
#include <termios.h> // POSIX terminal control definitions
#include <string>
#include <sstream>
#include <vector>
char * testSerialComm(int USB)
{
/* *** Configure Port *** */
struct termios tty;
memset (&tty, 0, sizeof tty);
/* Error Handling */
if ( tcgetattr ( USB, &tty ) != 0 )
{
std::cout << "Error " << errno << " from tcgetattr: " << strerror(errno) << std::endl;
}
/* Set Baud Rate */
cfsetospeed (&tty, B9600);
cfsetispeed (&tty, B9600);
/* Setting other Port Stuff */
tty.c_cflag &= ~PARENB; // Make 8n1
tty.c_cflag &= ~CSTOPB;
tty.c_cflag &= ~CSIZE;
tty.c_cflag |= CS8;
tty.c_cflag &= ~CRTSCTS; // no flow control
tty.c_lflag = 0; // no signaling chars, no echo, no canonical processing
tty.c_oflag = 0; // no remapping, no delays
tty.c_cc[VMIN] = 0; // read doesn't block
tty.c_cc[VTIME] = 15; // 0.5 seconds read timeout
tty.c_cflag |= CREAD | CLOCAL; // turn on READ & ignore ctrl lines
tty.c_iflag &= ~(IXON | IXOFF | IXANY);// turn off s/w flow ctrl
tty.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); // make raw
tty.c_oflag &= ~OPOST; // make raw
/* Flush Port, then applies attributes */
tcflush( USB, TCIFLUSH );
if ( tcsetattr ( USB, TCSANOW, &tty ) != 0)
{
std::cout << "Error " << errno << " from tcsetattr" << std::endl;
}
/* *** WRITE *** */
unsigned char cmd[] = {'I', 'N', 'I', 'T', ' ', '\r', '\0'};
int n_written = write( USB, cmd, sizeof(cmd) -1 );
/* Allocate memory for read buffer */
char buf [1024];
memset (&buf, '\0', sizeof buf);
/* *** READ *** */
int n = read( USB, &buf , sizeof buf );
/* Error Handling */
if (n < 0)
{
std::cout << "Error reading: " << strerror(errno) << std::endl;
}
/* Print what I read... */
return buf;
close(USB);
}
int main() {
/* Open File Descriptor */
int USB = open( "/dev/tty.usbmodem14201", O_RDONLY | O_NDELAY | O_NONBLOCK);
/* Error Handling */
if ( USB < 0 )
{
std::cout << "Error " << errno << " opening " << "/dev/ttyUSB0" << ": " << strerror (errno) << std::endl;
}
while(true){
std::string g = testSerialComm(USB);
std::stringstream stringStream(g);
std::string segment;
std::vector<std::string> seglist;
while(std::getline(stringStream, segment))
{
seglist.push_back(segment);
}
for(int i = 0; i < seglist.size(); i++){
std::string s = seglist[i];
if( g != ""){
if(s.find("$GNGLL") != std::string::npos){
std::cout << g ;
if(s.find(",,,,,") != std::string::npos){
std::cout << "Keine Position erkannt" << std::endl;
}
else{
std::cout << "s = " << s;
std::stringstream stringStream(s);
std::string segment2;
std::vector<std::string> seglist2;
while(std::getline(stringStream, segment))
{
seglist2.push_back(segment2);
}
std::cout << "Lat: "<< seglist2[1] << " " << seglist2[2] << std::endl;
std::cout << "Lon: "<< seglist2[3] << " " << seglist2[4] << std::endl;
std::cout << "UTC Time: " << seglist2[5] << std::endl;
}
}
}
}
}
return 0;
}
输出看起来像这样：
$GNVTG,,T,,M,1.346,N,2.493,K,A*31
$GNGGA,162555.00,5219.07535,N,01337.93745,E,1,06,2.06,41.2,M,42.1,M,,*71
$GNGSA,A,3,08,21,13,15,27,05,,,,,,,3.73,2.06,3.11*11
$GNGSA,A,3,,,,,,,,,,,,,3.73,2.06,3.11*1C
$GPGSV,3,1,11,04,15,114,15,05,51,227,14,07,34,067,18,08,15,050,24*7F
$GPGSV,3,2,11,09,00,116,,13,57,291,09,15,24,295,19,21,10,325,12*75
$GPGSV,3,3,11,27,07,017,09,28,45,149,,30,68,074,20*4F
$GLGSV,1,1,01,,,,23*65
$GNGLL,5219.07535,N,01337.93745,E,162555.00,A,A*76
$GNRMC,162556.00,A,5219.07530,N,01337.93762,E,0.984,,071119,,,A*$GPGSV,3,1,11,04,15,114,15,05,51,227,14,07,34,067,18,08,15,050,24*7F
$GPGSV,3,2,11,09,00,116,,13,57,291,10,15,24,295,19,21,10,325,11*7E
$GPGSV,3,3,11,27,07,017,09,28,45,149,,30,68,074,20*4F
$GLGSV,1,1,01,,,,22*64
$GNGLL,5219.07530,N,01337.93762,E,162556.00,A,A*75
$GNRMC,162557.00,A,5219.07530,N,01337.93755,E,1.021,,071119,,,A*64
$GNVTG,,T,,M,1.021,N,1.890,K,A*3F
$GNGGA,162557.00,5219.07530,N,01337.93755,E,1,06,2.06,40.8,M,42.1,M,,*7C
$GNGSA,A,3,08,21,13,15,27,05,,,,,,,3.72,2.06,3.10*11
$GNGSA,A,3,,,,,,,,,,,,,3.72,2.06,3.10*1C
$GPGSV,3,1,11,04,15,114,15,05,51,227,14,07,34,067,19,08,15,050,23*79
$GPGSV,3,2,11,09,00,116,,13,57,291,12,15,24,295,19,21,10,325,09*75
$GPGSV,3,3,11,27,07,017,11,28,45,149,,30,68,074,19*4C
$GLGSV,1,1,01,,,,22*64
$GNGLL,5219.07530,N,01337.93755,E,162557.00,A,A*70
$GNRMC,162558.00,A,5219.07513,N,01337.93724,E,0.889,,071119,,,A*67
$GNVTG,,T,,M,0.889,N,1.646,K,A*31
$GNGGA,162558.00,5219.07513,N,01337.93724,E,1,06,2.06,40.8,M,42.1,M,,*74
$GNGSA,A,3,08,21,13,15,27,05,,,,,,,3.72,2.06,3.10*11
$GNGSA,A,3,,,,,,,,,,,,,3.72,2.06,3.10*1C
$GPGSV,3,1,11,04,15,114,13,05,51,227,14,07,34,067,20,08,15,050,22*74
$GPGSV,3,2,11,09,00,116,,13,57,291,10,15,24,295,19,21,10,325,13*7C
$GPGSV,3,3,11,27,07,017,09,28,45,149,,30,68,074,19*45
$GLGSV,1,1,01,,,,23*65
$GNGLL,5219.07513,N,01337.93724,E,162558.00,A,A*78
$GNRMC,162559.00,A,5219.07523,N,01337.93720,E,0.766,,071119,,,A*$GNGSA,A,3,,,,,,,,,,,,,3.72,2.06,3.10*1C
$GPGSV,3,1,11,04,15,114,12,05,51,227,14,07,34,067,19,08,15,050,23*7E
$GPGSV,3,2,11,09,00,116,,13,57,291,10,15,24,295,19,21,10,325,11*7E
$GPGSV,3,3,11,27,07,017,08,28,45,149,,30,68,074,18*45
$GLGSV,1,1,01,,,,23*65
$GNGLL,5219.07523,N,01337.93720,E,162559.00,A,A*7E
Keine Position erkannt
$GNRMC,162600.00,A,5219.07611,N,01337.93712,E,0.764,,071119,,,A*$GPGSV,3,3,11,27,07,017,13,28,45,149,,30,68,074,19*4E
$GLGSV,1,1,01,,,,22*64
$GNGLL,5219.07611,N,01337.93712,E,162600.00,A,A*72
$GNRMC,162601.00,A,5219.07575,N,01337.93735,E,0.483,,071119,,,A*6E
$GNVTG,,T,,M,0.483,N,0.895,K,A*36
$GNGGA,162601.00,5219.07575,N,01337.93735,E,1,06,2.05,40.3,M,42.1,M,,*73
$GNGSA,A,3,08,21,13,15,27,05,,,,,,,3.72,2.05,3.10*12
$GNGSA,A,3,,,,,,,,,,,,,3.72,2.05,3.10*1F
$GPGSV,3,1,11,04,15,114,13,05,51,227,15,07,34,067,19,08,15,050,23*7E
$GPGSV,3,2,11,09,00,116,,13,57,291,10,15,24,295,18,21,10,325,13*7D
$GPGSV,3,3,11,27,07,017,12,28,45,149,,30,68,074,19*4F
$GLGSV,1,1,01,,,,22*64
$GNGLL,5219.07575,N,01337.93735,E,162601.00,A,A*77
Keine Position erkannt
$GNRMC,162602.00,V,,,,,,,071119,,,N*6D
$GNVTG,,,,,,,,,N*2E
$GNGGA,162602.00,,,,,0,05,15.84,,,,,,*74
$GNGSA,A,1,08,21,15,27,05,,,,,,,,36.98,15.84,33.41*28
$GNGSA,A,1,,,,,,,,,,,,,36.98,15.84,33.41*27
$GPGSV,3,1,11,04,15,114,12,05,51,227,16,07,34,067,19,08,15,050,22*7D
$GPGSV,3,2,11,09,00,116,,13,57,291,06,15,24,295,17,21,10,325,17*71
$GPGSV,3,3,11,27,07,017,08,28,45,149,,30,68,074,18*45
$GLGSV,1,1,01,,,,23*65
$GNGLL,,,,,162602.00,V,N*55
Keine Position erkannt
$GNRMC,162603.00,A,5219.07421,N,01337.93894,E,0.811,,071119,,,A*$GNGSA,A,3,,,,,,,,,,,,,3.72,2.05,3.10*1F
$GPGSV,3,1,11,04,15,114,10,05,51,227,15,07,34,067,18,08,15,050,21*7E
$GPGSV,3,2,11,09,00,116,,13,57,291,09,15,24,295,17,21,10,325,10*79
$GPGSV,3,3,11,27,07,017,07,28,45,149,,30,68,074,18*4A
$GLGSV,1,1,01,,,,23*65
$GNGLL,5219.07421,N,01337.93894,E,162603.00,A,A*71
Keine Position erkannt
$GNRMC,162604.00,A,5219.07430,N,01337.93925,E,0.640,,071119,,,A*69
$GNVTG,,T,,M,0.640,N,1.186,K,A*31
$GNGGA,162604.00,5219.07430,N,01337.93925,E,1,06,2.05,40.8,M,42.1,M,,*72
$GNGSA,A,3,08,21,13,15,27,05,,,,,,,3.72,2.05,3.10*12
$GNGSA,A,3,,,,,,,,,,,,,3.72,2.05,3.10*1F
$GPGSV,3,1,11,04,15,114,,05,51,227,14,07,34,067,18,08,15,050,21*7E
$GPGSV,3,2,11,09,00,116,,13,57,291,09,15,24,295,18,21,10,325,18*7E
$GPGSV,3,3,11,27,07,017,08,28,45,149,,30,68,074,18*45
$GLGSV,1,1,01,,,,22*64
$GNGLL,5219.07430,N,01337.93925,E,162604.00,A,A*7D
Process finished with exit code 15
我遇到了几个问题：
首先：每次插拔电源时，usb设备的名称都会更改。唯一改变的是数字。因此它从以下更改：
/dev/tty.usbmodem14201
收件人：
/dev/tty.usbmodem14101
如何找到正确的设备名称？
第二个问题： 我想从GPS传感器获取位置。如果它有位置，则消息看起来像这样：
$GNGLL,,,,,162602.00,V,N*55
获得职位后，它看起来像这样：
$GNGLL,5219.07430,N,01337.93925,E,162604.00,A,A*7D
坐标在第二和第四段中： $ GNGLL， 5219.07430 ，N， 01337.93925 ，E，162604.00，A，A * 7D
我的主要问题是，我想逐行读取设备，但是read( USB, &buf , sizeof buf );方法不适合这种情况。
答案 0 :(得分：0)
#$GNGLL decoder
import serial
port = "/dev/ttyS0"
def parseGPS(data):
# print "raw:", data #prints raw data
if data[0:6] == "$GNGLL":
sdata = data.split(",")
if sdata[2] == 'V':
print "no satellite data available"
return
print "---Parsing GNGLL---",
time = sdata[5][0:2] + ":" + sdata[5][2:4] + ":" + sdata[5][4:6]
lat = decode(sdata[1]) #latitude
lon = decode(sdata[3]) #longitute
print time+" "+lat+" "+lon
def decode(coord):
#Converts DMS to decimal system
if(coord[0:1]=='0'):
gps = coord[1:3]
else:
gps=coord[0:2]
gps1=float(gps)+round((float(coord)/60)%10,4)
return str(gps1)
print "Receiving GPS data"
ser = serial.Serial(port, baudrate = 9600, timeout = 0.5)
while True:
data = ser.readline()
parseGPS(data)