HS121L/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"

//on_off : 0, 拉低IO
//on_off : 1, 拉高IO
void GPS_RFPwrCtrl(char on_off)
{
	static unsigned char firstIn=0;
	char buf[20];
	unsigned char status=0;
	
	if(on_off) status=1;
	
	if(firstIn==0)
	{
		firstIn++;
		os_dly_wait(10);
		ModemSendAT("AT^GPIOINIT=1\r\n");//初始化GPIO驱动
		os_dly_wait(10);
		ModemSendAT("AT^GPIOCFG=1,3,1\r\n");//使能GPS_RFPWR_EN [PIN56]
	}
	os_dly_wait(10);
	sprintf(buf, "AT^GPIOSET=3,%d\r\n",status);
	ModemSendAT(buf);
}

/**********************************************************************************
GPSInit
***********************************************************************************/
void 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_PWR_PIN;
	GPIO_Init(GPS_PWR_PORT, &GPIO_InitStructure);
	
	GPS_PWR_ON;
}

void GPSRestart(void)
{
	g_usRx3Len=0;
  rx3_ct=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;
}

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