#include "Adafruit_MAX31855.h"
#include <LiquidCrystal.h>

int thermoDO = 5;
int thermoCS1 = 4;
int thermoCS2 = 2;
int thermoCLK = 3;
int startstop = 8;
int mode      = 9;
int relaypin  = 6;

int state = 0;

boolean started = 0;
boolean startstoppressed = 0;
boolean modepressed = 0;

int profiles = 0;

int profile[4][6] = {
  {
    75,140,45,125,205,20                                    }
  ,
  {
    75,140,45,125,205,20                                    }
  ,
  {
    75,140,45,125,205,20                                    }
  ,
  {
    75,140,45,125,205,20                                    }
};

String profileNames[4] = {
  "Ol' Fashioned Pb", "New Fangled RoHS", "Profile 3       ", "Profile 4       "
};


Adafruit_MAX31855 thermocouple1(thermoCLK, thermoCS1, thermoDO);
Adafruit_MAX31855 thermocouple2(thermoCLK, thermoCS2, thermoDO);

LiquidCrystal lcd(A0, A1, A2, A3, A4, A5);

// volatile means it is going to be messed with inside an interrupt 
// otherwise the optimization code will ignore the interrupt

volatile float seconds = 0;  // this will get incremented once a second
volatile long count = 0;
volatile int lcdCount = 0;
volatile float temp_avg;  // in celsius
volatile float temp1 = 0;
volatile float temp2 = 0;

// the current temperature
int target_temperature;

// we need this to be a global variable because we add error each second
float Summation;        // The integral of error since time = 0

int relay_state;       // whether the relay pin is high (on) or low (off)

void setup() {  
  Serial.begin(9600); 

  // set up the LCD's number of columns and rows: 
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("Reflow Oven");
  lcd.setCursor(0,1);
  lcd.print("Rev 2");

  delay(1000);
  lcd.clear();

  lcd.setCursor(15,1);
  lcd.print(state);

  lcd.setCursor(0,0);
  lcd.print(profileNames[profiles]);

  lcd.setCursor(0,1);
  lcd.print("Temp: ");
  lcd.setCursor(6,1);
  lcd.print((int)seconds);
  lcd.print(" C   "); 

  // the relay pin controls the plate
  pinMode(relaypin, OUTPUT);
  // ...and turn it off to start!
  digitalWrite(relaypin, LOW);

  pinMode(startstop, INPUT);
  digitalWrite(startstop, HIGH);

  pinMode(mode, INPUT);
  digitalWrite(mode,HIGH);

  // Setup 1 Hz timer to refresh display using 16 Timer 1
  TCCR1A = 0;                           // CTC mode (interrupt after timer reaches OCR1A)
  TCCR1B = _BV(WGM12) | _BV(CS10) | _BV(CS12);    // CTC & clock div 1024
  OCR1A = 3902;                                 // 16mhz / 1024 / 15609 = 1 Hz
  TIMSK1 = _BV(OCIE1A);                          // turn on interrupt
}


// This is the Timer 1 CTC interrupt, it goes off once a second
SIGNAL(TIMER1_COMPA_vect) { 

  float temp_temp;
  float previous_temp1 = temp1;
  float previous_temp2 = temp2;
  int error;

  count ++;
  seconds = (float) count / 4;

  temp_temp = thermocouple1.readCelsius();
  if (isnan(temp_temp)){
    temp1 = previous_temp1; 
  }
  else{
    temp1 = temp_temp; 
  }

  temp_temp = thermocouple2.readCelsius();
  if (isnan(temp_temp)){
    temp2 = previous_temp2; 
  }
  else{
    temp2 = temp_temp; 
  }

  temp_avg = (temp1 + temp2)/2;

  lcd.setCursor(0,1);
  lcd.print("Temp: ");
  lcd.setCursor(6,1);
  lcd.print(temp_avg);
  lcd.print(" C   ");  
  lcd.setCursor(15,1);
  lcd.print(state);

  switch(state){
  case 0:
    digitalWrite(relaypin, LOW);
    break;  

  case 1:
    analogWrite(relaypin,profile[profiles][0]);
    if (temp_avg >= profile[profiles][1]){
      state = 2;
      count = 0;  
    }
    break;  

  case 2:
    if (temp_avg < profile[profiles][1])
      digitalWrite(relaypin, HIGH);
    else
      digitalWrite(relaypin, LOW);
    if (seconds >= profile[profiles][2]){
      state = 3;  
    }
    break;  

  case 3:
    analogWrite(relaypin,profile[profiles][3]);
    if (temp_avg >= profile[profiles][4]){
      state = 4;
      count = 0;  
    }
    break;  

  case 4:
    if (temp_avg < profile[profiles][4])
      digitalWrite(relaypin, HIGH);
    else
      digitalWrite(relaypin, LOW);
    if (seconds >= profile[profiles][5]){
      state = 0;  
      digitalWrite(relaypin, LOW);
    }
    break;  

  default:
    digitalWrite(relaypin, LOW);
    state = 0;
    count = 0;
    break;  
  }

  if (digitalRead(startstop) == LOW && !startstoppressed){
    startstoppressed = 1;
    lcd.setCursor(15,1);
    lcd.print(state);
    if (started == 1){
      started = 0;
      state = 0;
      digitalWrite(relaypin, LOW);
    }
    else{
      started = 1; 
      state = 1;
    } 
  }
  if (digitalRead(startstop) == HIGH)
    startstoppressed = 0;

  if (digitalRead(mode) == LOW && !modepressed){
    modepressed = 1;
    if (profiles < 3)
      profiles++;
    else
      profiles = 0;

    lcd.setCursor(0,0);
    lcd.print(profileNames[profiles]);
  }  
  if (digitalRead(mode) == HIGH)
    modepressed = 0;
}

void loop() { 

}