M21/user/GPS/GPS.c

 /**********************************************************************************
 * File Name: GPS.c
 * Function Describe:device for GPS	
 * Relate Module:
 * Explain:	the GPS should be using ublox 
 * Writer:  ShiLiangWen
 * Date:	2015.1.26
***********************************************************************************/
#define THIS_FILE_ID 9
//------------------------------------------------------------------------------------
#include "includes.h"
/**********************************************************************************
GPSInit
***********************************************************************************/
int GPSInit(void)
{
	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_InitStructure.GPIO_Pin = GPS_PWREN_PIN;
	GPIO_Init(GPS_PWREN_PORT, &GPIO_InitStructure);
	SlwTrace(INF,"GPSInit...",1);
	sutGpsInfo.isGpsWork=0;
	sutGpsInfo.isGpsValid=0;
	sutGpsInfo.GpsInactiveCt=0;
	GPS_PWREN_HIGH;
	//GPS_PWREN_LOW;
	return 0;
}
/************************************
GPSGetGPRMC
从NEMA数据流中提取$GPRMC行并返回
************************************/
char* GPSGetGPRMC(char *msg)
{
/************************************
$GPGGA,235957.003,,,,,0,0,,,M,,M,,*44
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,1,1,00*79
$GPRMC,235957.003,V,,,,,0.00,0.00,050180,,,N*4D
************************************/
	char *p=msg;
	char ch1,ch2;
	ch1=*p;
	while(ch1){
		ch2=ch1;
		ch1=*p++;
		if(ch2==0xD && ch1==0x0A){
			if(p[0]=='$' && p[3]=='R' && p[5]=='C'){ //$GPRMC
				return p;
			}
		}
	}
	return 0;
}

/***********************************************************************************/