#include <SoftwareSerial.h>
#include <TinyGPS.h>
#include <SPI.h>
#include <SD.h>


const int chipSelect = 10;
bool newData = false;
unsigned long chars;
unsigned short sentences, failed;
float flat, flon;
char c;

TinyGPS gps;
SoftwareSerial ss(6, 7); //(TX,RX)


void setup() 

{
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.begin(9600);
  ss.begin(9600);
  
  Serial.print("GPS library v. ");
  Serial.println(TinyGPS::library_version());
  
  while (!Serial) 
  {
    ; // wait for serial port to connect. Needed for native USB port only
  }


  Serial.print("SD library...");
  
  if (!SD.begin(chipSelect)) 
  {
    Serial.println("Card failed, or not present");
    return;
  }
  Serial.println("Card initialized.");
}


void loop()
{
  // This sketch displays information every time a new sentence is correctly encoded.
  while (ss.available() > 0)
  {
    if (gps.encode(ss.read()))
    {
      displayInfo();
    }
  }
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(100);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(100);                       // wait for a second

}


void displayInfo()
{
  String dataString = "";
  unsigned long age;
  Serial.print(("Location: ")); 
  gps.f_get_position(&flat, &flon, &age);
  
  flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flat, 6;
  flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flat, 6;
  

  dataString += String(flat);
  dataString += ",";
  dataString += String(flon);

  File dataFile = SD.open("datalog.txt", FILE_WRITE);
  if (dataFile) 
  {
    dataFile.println(dataString);
    dataFile.close();
    Serial.println(dataString);
  }
  else 
  {
    Serial.println("error opening datalog.txt");
  }
}