#include <string.h>

#include <SoftwareSerial.h>

//#include <SPI.h>
#include <SD.h>

//#define CS 4  //Required Chip select for Eternet Shield
#define CS 10  //Required Chip select for Interface Shield
#define LED 13
//#define SW 5
//#define SS 10

SoftwareSerial gps( 6, 7 );


int i;
char msg[256];
char flg;


void setup()
{
  pinMode(CS, OUTPUT);
  pinMode(LED, OUTPUT);
  //pinMode(SW, INPUT);


 
  gps.begin(9600);
  Serial.begin(9600);
  Serial.println("--- GPS Logger ---");

  if(SD.begin(CS)==true) {
    Serial.println("SD Card Activate.");
    SD.remove("GPS_LOG.LOG");
  } else {
    Serial.println("SD Card Not Active!!");
    digitalWrite(LED, HIGH);
  }

  delay(3000);

  digitalWrite(LED, HIGH);
  delay(200);
  digitalWrite(LED, LOW);
  delay(200);
  digitalWrite(LED, HIGH);
  delay(200);
  digitalWrite(LED, LOW);
  delay(200);
  digitalWrite(LED, HIGH);
  delay(200);
  digitalWrite(LED, LOW);
  
  Serial.println("---> Logging Start!!...");
  i=0;
  flg = 0;
  Serial.flush();
}

void loop()
{
//  if(flg == 1 ) {
//    return;
//  }
  do {
    if (gps.available()) {
      msg[i++]=gps.read();
    }
    if (i > 254) break;
  } while(msg[i-1] != 0x0a);
  msg[i]=0x00;
  if ((strncmp("$GPGGA", msg, 6)==0) || (strncmp("$GPRMC", msg, 6)==0)) {
    Serial.print(msg);  
  }
  
  digitalWrite(LED, HIGH);
  File sdFile=SD.open("gps_log.log",FILE_WRITE);
  sdFile.print(msg);
  sdFile.close();
  digitalWrite(LED, LOW);
  i=0;
//  if (digitalRead(SW) == HIGH) {
//    flg = 1;
//  }
}