/*
  SD card datalogger
 
 
 */

#include <SD.h>
#include <Wire.h>
#include "RTClib.h"
#include "Adafruit_MAX31855.h"
#define DP 1  // No. decimal places for serial output

RTC_DS1307 rtc;  //call library for clock

//assign variables for max31855
const int chipSelect = 10;
const int thermoCLK = 3;
const int thermoCS = 4;
const int thermoDO = 5;

Adafruit_MAX31855 thermocouple(thermoCLK, thermoCS, thermoDO);  // initialize the thermocouple

void setup() {
  Serial.begin(57600);  // Open serial communications and wait for port to open:
   
  #ifdef AVR
  Wire.begin();
  #endif
  rtc.begin();

  if (! rtc.isrunning()) {
    Serial.println("RTC is NOT running!");
    
    // following line sets the RTC to the date & time this sketch was compiled
    // This line sets the RTC with an explicit date & time, for example to set
    // January 21, 2014 at 3am you would call:
    // rtc.adjust(DateTime(2014, 1, 21, 3, 0, 0));
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }

 Serial.print("Initializing SD card...");
  
  // make sure that the default chip select pin is set to output, even if you don't use it:
  pinMode(10, OUTPUT);
  
  // see if the card is present and can be initialized:
  if (!SD.begin(chipSelect)) {
    Serial.println("Card failed, or not present");
    // don't do anything more:
    return;
  }
  Serial.println("card initialized.");
  
  Serial.println("MAX31855 test");
  // wait for MAX chip to stabilize
  delay(1000);
}

void loop(){
  
  DateTime now = rtc.now();
  
  //print date & time to serial  
    Serial.print(now.year(), DEC);
    Serial.print('/');
    Serial.print(now.month(), DEC);
    Serial.print('/');
    Serial.print(now.day(), DEC);
    Serial.print(' ');
    Serial.print(now.hour(), DEC);
    Serial.print(':');
    Serial.print(now.minute(), DEC);
    Serial.print(':');
    Serial.print(now.second(), DEC);
    Serial.println();
  
   // basic readout test, just print the current temp
   Serial.print("Internal Temp = ");
   Serial.println(thermocouple.readInternal());
   
   doOver:  //reset to here if tc reading isnan

   float f = thermocouple.readFarenheit();  //read tc and store in variable
   
   if (isnan(f)) {
     Serial.println("Something wrong with thermocouple!");
     Serial.print("errorBit = ");  //read error bit and write to serial
     Serial.println(thermocouple.readError());
     delay(1000);  //wait a second, then read tc again
     goto doOver;

     
   } else {
     
    Serial.print("F = ");
    Serial.println(f);
   
 


  File dataFile = SD.open("datalog.txt", FILE_WRITE);  // open the file

  
  if (dataFile) {  // if the file is available, write to it:
    DateTime now = rtc.now();  //variable to store data/time
    
    //write date & time to SD card
    dataFile.print(now.year(), DEC);
    dataFile.print('/');
    dataFile.print(now.month(), DEC);
    dataFile.print('/');
    dataFile.print(now.day(), DEC);
    dataFile.print(' ');
    dataFile.print(now.hour(), DEC);
    dataFile.print(':');
    dataFile.print(now.minute(), DEC);
    dataFile.print(':');
    dataFile.print(now.second(), DEC);
    dataFile.println();
   
    
 //wirte temp to SD card
    dataFile.print("F = ");
    dataFile.println(f);
    dataFile.close();
    // print to the serial port too:
    Serial.println();
  }  
  // if the file isn't open, pop up an error:
  else {
    Serial.println("error opening datalog.txt");
  } 
  delay(300000);  //wait 5 min before next read/write
  }
}