gps.c

GPS的一个几码程序

#include <termios.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/signal.h>
#include <pthread.h>
#include <string.h>
#include <stdlib.h>  // Must include . or, the result is wrong!!!!!!!!!
  
#include     "serial.h"
#include     "gps.h"
#include     "comm.h"

#define USE_BEIJING_TIMEZONE
#define MAXMSGLEN 256

char GPS_BUF[MAXMSGLEN];
GPS_INFO gps_info;
 
int GetCharPos(int num,char* str);
void UTC2BTC(date_time *GPS);
double get_double_number(char *s);

////////////////////////////////////////////////////////////////////////
// Test main()
//
#if 1   

#define ENDMINITERM 27 /* ESC to quit miniterm */
volatile int STOP=FALSE;
void child_handler(int s);
void* keyboard(void * data);
void* receive(void * data);
void* show_gps_info(void * data);



int main(int argc,char** argv)
{	
	struct sigaction sa;
	int ok;
 	pthread_t th_a, th_b, th_c;
 	void * retval;	
 	
  	GPS_Init();

  	sa.sa_handler = child_handler;
  	sa.sa_flags = 0;
  	sigaction(SIGCHLD,&sa,NULL); /* handle dying child */

  	pthread_create(&th_a, NULL, keyboard, 0);
  	pthread_create(&th_b, NULL, receive, 0);

  	pthread_join(th_a, &retval);
  	pthread_join(th_b, &retval);
 
  	printf("exit main 1\n");
  	close(fd2);
	printf("exit main 2\n");
return(0);	
}
void child_handler(int s)
{
  printf("stop!!!\n");
   STOP=TRUE;
}
void* keyboard(void * data)
{
    int c;
    c=getchar();
    STOP=TRUE;
	printf("exit keyboard\n");
    return NULL;
}
void* receive(void * data)
{
	int i=0, tmp=0;
	char c;
	char buf[256];
  
	GPS_INFO GPS;

	while (STOP==FALSE) {		
		//tmp = read(fd2,&c,1);  /* 直接阻塞读串口 */
		tmp = readport(fd2,2000,&c);
	  	buf[i++] = c;
		
		if(c == '\n'){			
			buf[i]='\0';
			i=0;
     		if( buf[5]=='C' || (buf[4]=='G'&&buf[5]=='A')){        //"GPRMC"  "$GPGGA"
				strcpy(GPS_BUF, buf);       			
				gps_parse(GPS_BUF,&gps_info);
				show_gps(&gps_info);
				printf("%s", GPS_BUF);
   			}
			
		}
    }	
    printf("exit from reading modem\n");
    return NULL; 
}

#endif
//
// Test main()
////////////////////////////////////////////////////////////////////////

void GPS_Init()
{
  fd2 = OpenDev(COM2);  
  set_speed(fd2,4800);	//设置开发平台的串口2波特率
  if (set_Parity(fd2,8,1,'N') == FALSE)  {
		printf("Set Parity Error\n");
		exit (0);
  } 
  usleep(1000000);  
}


void show_gps(GPS_INFO *GPS)
{
	printf("DATE       : %d-%02d-%02d \n",GPS->D.year,GPS->D.month,GPS->D.day);
	printf("TIME       :  %02d:%02d:%02d \n",GPS->D.hour,GPS->D.minute,GPS->D.second);
	printf("Latitude   : %.4f %c\n",GPS->latitude,GPS->NS);
	printf("Longitude  : %.4f%c\n",GPS->longitude,GPS->EW);
	printf("Highness   : %.4f \n",GPS->high);
	printf("STATUS     : %c\n",GPS->status);
}

////////////////////////////////////////////////////////////////////////////////
//解释gps
//0      7  0   4 6   0     6 8 0        90         0  3      0        9
//$GPRMC,091400,A,3958.9870,N,11620.3278,E,000.0,000.0,120302,005.6,W*62
//$GPGGA,091400,3958.9870,N,11620.3278,E,1,03,1.9,114.2,M,-8.3,M,,*5E

void gps_parse(char *line,GPS_INFO *GPS)
////////////////////////////////////////////////////////////////////////////////
{
	int tmp;
	char c;
	char* buf=line;
	c=buf[5];

 if(buf[0]!='$')return;
 
	if(c=='C'){//"GPRMC"
  
		GPS->D.hour   =(buf[ 7]-'0')*10+(buf[ 8]-'0');
		GPS->D.minute =(buf[ 9]-'0')*10+(buf[10]-'0');
		GPS->D.second =(buf[11]-'0')*10+(buf[12]-'0');
		tmp = GetCharPos(9,buf);
		GPS->D.day    =(buf[tmp+0]-'0')*10+(buf[tmp+1]-'0');
		GPS->D.month  =(buf[tmp+2]-'0')*10+(buf[tmp+3]-'0');
		GPS->D.year   =(buf[tmp+4]-'0')*10+(buf[tmp+5]-'0')+2000;
		//------------------------------
		GPS->status	  =buf[GetCharPos(2,buf)];
		GPS->latitude =get_double_number(&buf[GetCharPos(3,buf)]);
		GPS->NS       =buf[GetCharPos(4,buf)];
		GPS->longitude=get_double_number(&buf[GetCharPos(5,buf)]);
		GPS->EW       =buf[GetCharPos(6,buf)];
#ifdef USE_BEIJING_TIMEZONE
		UTC2BTC(&GPS->D);
#endif
	}
	if(c=='A'){ //"$GPGGA"
		GPS->high     = get_double_number(&buf[GetCharPos(9,buf)]); 
	}
}

double get_double_number(char *s)
{
	char buf[128];
	int i;
	double rev;
	i=GetCharPos(1,s);
	strncpy(buf,s,i);
	buf[i-1]='\0';         
	rev=atof(buf);          
	return rev;

}

////////////////////////////////////////////////////////////////////////////////
//
int GetCharPos(int num,char *str)
{
	int i,j=0;
	int len=strlen(str);
	for(i=0;i<len;i++)
	{
		if(str[i]==',')j++;
		if(j==num)return i+1;
	}
	return 0;
}


//#ifdef USE_BEIJING_TIMEZONE
////////////////////////////////////////////////////////////////////////////////
//
void UTC2BTC(date_time *GPS)
{

//***************************************************
//如果秒号先出,再出时间数据,则将时间数据+1
		GPS->second++; //
		if(GPS->second>59){
			GPS->second=0;
			GPS->minute++;
			if(GPS->minute>59){
				GPS->minute=0;
				GPS->hour++;
			}
		}

//***************************************************
		GPS->hour+=8;
		if(GPS->hour>23)
		{
			GPS->hour-=24;
			GPS->day+=1;
			if(GPS->month==2 ||
			   		GPS->month==4 ||
			   		GPS->month==6 ||
			   		GPS->month==9 ||
			   		GPS->month==11 ){
				if(GPS->day>30){
			   		GPS->day=1;
					GPS->month++;
				}
			}
			else{
				if(GPS->day>31){
			   		GPS->day=1;
					GPS->month++;
				}
			}
			if(GPS->year % 4 == 0 ){//
		   		if(GPS->day > 29 && GPS->month ==2){
		   			GPS->day=1;
					GPS->month++;
				}
			}
			else{
		   		if(GPS->day>28 &&GPS->month ==2){
		   			GPS->day=1;
					GPS->month++;
				}
			}
			if(GPS->month>12){
				GPS->month-=12;
				GPS->year++;
			}
		}
}

void ReceiveOneBL( GPS_INFO* GPS_info)
{
	int i=0, tmp=0;
	char c;
	char buf[256];	
  
	while (1) {		
	  tmp = read(fd2,&c,1);  
	  buf[i++] = c;
	  if(c == '\n'){			
	    buf[i]='\0';
	    i=0;	    
     	    if( buf[5]=='C'&&buf[0]=='$') break;           //完整的"GPRMC"	   		  		
	  }
  	}
	gps_parse(buf,GPS_info);	
  return ; 
}