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我想从RS232串口上读取GPS发送的数据
但是读出来的总是
2014/05/20 14:50:00 E00000.0000 N0000.0000
2014/05/20 14:50:03 E00000.0000 N0000.0000
2014/05/20 14:50:06 E00000.0000 N0000.0000
2014/05/20 14:50:10 E00000.0000 N0000.0000
2014/05/20 14:50:12 E00000.0000 N0000.0000
2014/05/20 14:50:15 E00000.0000 N0000.0000
2014/05/20 14:50:19 E00000.0000 N0000.0000
不知道是什么原因
程序如下
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <string.h>
#include <time.h>
#define FALSE -1
#define TRUE 0
#define lianpai 3
void set_speed(int fd,int speed);
int OpenDev (char *Dev);
int set_Parity(int fd,int databits,int stopbits,int parity);
int main(int argc,char **argv) {
unsigned char rbuff[512];
int fd,i,ii,iii,tmpi;
int nread,nnread;
char *dev ="/dev/ttySAC1";
fd = OpenDev (dev);
set_speed(fd,4800); //4800
if (set_Parity(fd,8,1,'N')==FALSE){
printf("Set Parity Error\n" ;
exit(0);
} else printf("open com1 successfully\n";
usleep(5000);
char tm_hour[2],tm_min[2],tm_sec[3],tm_day[3];
char tm_mon[2],tm_year[5],latitude[11],longitude[11],NS,EW;//latitude jingdu
latitude[11]='\0';
longitude[11]='\0';
tm_year[1]='2';
tm_year[2]='0';
while(1){
char gpsdata[512];
nread=read(fd,rbuff,512);
tmpi=0;
for (iii=0;iii<8;iii++){
for (i=0;i<nread;i++){
gpsdata[tmpi+i]=rbuff[i];
if (tmpi+i==510){ break;}
}
tmpi=tmpi+nread;
nread=read(fd,rbuff,512);
}
gpsdata[511]='\0';
//output the gpsdata
//2012/12/20 11:31:09 E12025.7496 N3607.2785
// for (ii=0;ii<strlen(gpsdata);ii++){
// printf("%c",gpsdata[ii]);
// }
for (i=0;i<strlen(gpsdata);i++){
if((0x24==gpsdata[i])&&(0x43==gpsdata[i+5])){ //C 0x43 $ 0x24
tm_hour[0]=gpsdata[i+7];
tm_hour[1]=gpsdata[i+8];
// hour +8 beijing time
if((tm_hour[1]+ > '9') {tm_hour[0]=tm_hour[0]+1;
tm_hour[1]=tm_hour[1]+8-10;
}
else (tm_hour[1]=tm_hour[1]+;
tm_min[0]=gpsdata[i+9];
tm_min[1]=gpsdata[i+10];
tm_sec[0]=gpsdata[i+11];
tm_sec[1]=gpsdata[i+12];
ii=get_comma_position(gpsdata,i,9);
tm_year[3]=gpsdata[ii+5];
tm_year[4]=gpsdata[ii+6];
tm_mon[1]=gpsdata[ii+3];
tm_mon[2]=gpsdata[ii+4];
tm_day[1]=gpsdata[ii+1];
tm_day[2]=gpsdata[ii+2];
EW=gpsdata[get_comma_position(gpsdata,i,6)+1];
ii=get_comma_position(gpsdata,i,5);
for (tmpi=1;tmpi<=10;tmpi++) {
latitude[tmpi]=gpsdata[ii+tmpi];}
NS=gpsdata[get_comma_position(gpsdata,i,4)+1];
ii=get_comma_position(gpsdata,i,3);
for (tmpi=1;tmpi<=9;tmpi++) {
longitude[tmpi]=gpsdata[ii+tmpi];}
//output the gpsdata needed
for (i=1;i<=4;i++){printf("%c",tm_year[i]);}
printf("/";
for (i=1;i<3;i++){printf("%c",tm_mon[i]);}
printf("/";
for (i=1;i<3;i++){printf("%c",tm_day[i]);}
printf(" ";
for (i=0;i<2;i++){printf("%c",tm_hour[i]);}
printf(":";
for (i=0;i<2;i++){printf("%c",tm_min[i]);}
printf(":";
for (i=0;i<2;i++){printf("%c",tm_sec[i]);}
printf(" ";
printf("%C",EW);
for (i=1;i<=10;i++) {printf("%c",latitude[i]);}
printf(" ";
printf("%C",NS);
for (i=1;i<=9;i++){printf("%c",longitude[i]);}
printf("\n";
break;
}
}
tcflush(fd,TCIOFLUSH);
}
close(fd);
return 0;
return EXIT_SUCCESS;
}
int OpenDev (char *Dev)
{
int fd = open (Dev, O_RDWR );
if (-1==fd)
{
perror("Can't Open Serial Port");
return -1;
}
else
return fd;
}
int speed_arr[]={B38400,B19200,B9600,B4800,B38400,B19200,B9600,B4800};
int name_arr[]={38400,19200,9600,4800,38400,19200,9600,4800};
void set_speed(int fd,int speed){
int i;
int status;
struct termios Opt;
tcgetattr(fd,&Opt);
for (i=0;i<sizeof(speed_arr)/sizeof(int);i++){
if (speed==name_arr[i]){
tcflush(fd,TCIOFLUSH);
cfsetispeed(&Opt,speed_arr[i]);
cfsetospeed(&Opt,speed_arr[i]);
status=tcsetattr(fd,TCSANOW,&Opt);
if (status!=0){
perror("tcsetattr fd");
return;
}
tcflush(fd,TCIOFLUSH);
}
}
}
int set_Parity (int fd,int databits,int stopbits,int parity)
{
struct termios options;
if(tcgetattr(fd,&options)!= 0){
perror("SetupSerial 1");
return(FALSE);
}
options.c_cflag &=~CSIZE;
switch(databits)
{
case 7: options.c_cflag |=CS7;break;
case 8: options.c_cflag |=CS8;break;
default: fprintf(stderr,"Unsupported data size\n");return(FALSE);
}
switch(parity)
{
case 'n':
case 'N' ptions.c_cflag &=~PARENB; //clear parity enable
options.c_iflag &=~INPCK; //enable parity checking
break;
case 'o':
case 'O':
options.c_cflag |= (PARODD | PARENB);
options.c_iflag |= INPCK; //disable parity checking
break;
case 'e':
case 'E': options.c_cflag |= PARENB; //enable parity
options.c_cflag &= ~PARODD;
options.c_iflag |= INPCK; //disable parity checking
break;
case 'S':
case 's': //no parity
options.c_cflag &=~PARENB;
options.c_cflag&=~CSTOPB;
break;
default:
fprintf(stderr,"Unsupported parity \n");
return(FALSE);
}
switch(stopbits){
case 1: options.c_cflag &= ~CSTOPB;break;
case 2: options.c_cflag |= CSTOPB;break;
default:fprintf(stderr,"Unsupported stop bits \n");
return(FALSE);
}
//set input parity option
if (parity !='n')
options.c_iflag |=INPCK;
options.c_cflag|= (CLOCAL|CREAD);
options.c_lflag&=~(ICANON|ECHO|ECHOE|ISIG);
options.c_oflag&=~OPOST;
options.c_oflag&=~(ONLCR|OCRNL);
options.c_iflag&=~(ICRNL|INLCR);
options.c_iflag&=~(IXON|IXOFF|IXANY);
tcflush(fd,TCIFLUSH);
options.c_cc[VTIME]=100;//10 jie shou yi ge zijie dengdai chaoshi
options.c_cc[VMIN]=68; //68 in example zuishao zifu duqu shu
if (tcsetattr(fd,TCSANOW,&options)!=0 ){
perror("Setup Serial 1");
return(FALSE);
}
return(TRUE);
}
int get_comma_position(char gpsdata[512],int i,int n){
int tmpi,commanum=0;
for (tmpi=1;tmpi<=80;tmpi++){ //find the nineth comma
if (gpsdata[i+tmpi]==','){commanum+=1;}
if (commanum==n) {break;};
}
return (i+tmpi);
}
这是网上找的
我以为只要改串口的位置就能读取GPS的数据了
请问我想从串口读取数据，要怎么做呢？ |
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发表于 2014-05-20 14:53
发表于 2014-05-20 15:11
