//LCD Screen
#include <LiquidCrystal.h> // includes the LiquidCrystal Library 

LiquidCrystal lcd(14, 15, 4, 5, 6, 7); // Creates an LCD object. Parameters: (rs, enable, d4, d5, d6, d7) 

//PID
#include <PID_v1.h>

#define PIN_INPUT 0
#define RELAY_PIN 10

//Define Variables we'll be connecting to
double Setpoint, Input, Output;

//Specify the links and initial tuning parameters
double Kp=2, Ki=0, Kd=0;
PID myPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, DIRECT);

int WindowSize = 5000;
unsigned long windowStartTime;

//Thermistor
int ThermistorPin = 0;
int Vo;
float R1 = 10000;
float logR2, R2, T;
float c1 = 1.009249522e-03, c2 = 2.378405444e-04, c3 = 2.019202697e-07;
double TargetT;

// Buttons
//constants won't change. They're used here to set pin numbers:
const int buttonPin1 = 8;  // the number of the pushbutton pin
const int buttonPin2 = 9;  // the number of the pushbutton pin
const int ledPin = 13;    // the number of the LED pin
int buttonState1 = 0;  // variable for reading the pushbutton status
int buttonState2 = 0;  // variable for reading the pushbutton status
double buttonCount = 80;

// Relay pin is controlled with D10. The active wire is connected to Normally Closed and common
//int relay = 10;


void setup() {

 Serial.begin(9600);
 
  //LCD Setup
 lcd.begin(16,2); // Initializes the interface to the LCD screen, and specifies the dimensions (width and height) of the display } 
  
  //LED Light
  pinMode(13, OUTPUT);

  //Button
  pinMode(buttonPin1, INPUT);
  pinMode(buttonPin2, INPUT);

  //Relay
 // pinMode(relay, OUTPUT);
  //digitalWrite(relay, LOW);

//PID
windowStartTime = millis();

  //initialize the variables we're linked to
  Setpoint = buttonCount;

  //tell the PID to range between 0 and the full window size
  myPID.SetOutputLimits(0, WindowSize);

  //turn the PID on
  myPID.SetMode(AUTOMATIC);
    
    //turn the PID on
  myPID.SetMode(AUTOMATIC);

}

void loop() {
  //Thermistor
  Vo = analogRead(ThermistorPin);
  R2 = R1 * (1023.0 / (float)Vo - 1.0);
  logR2 = log(R2);
  T = (1.0 / (c1 + c2*logR2 + c3*logR2*logR2*logR2));
  T = T - 273.15;
  T = (T * 9.0)/ 5.0 + 32.0; 
  Input = T;

 //Serial Print 
  Serial.print("Temperature: ");
  Serial.print(T);
  Serial.println(" F");
 //Serial Print 
  Serial.print("Set Temp: ");
  Serial.print(Setpoint);
  Serial.println(" F");
   //Serial Print 
  Serial.print("Input: ");
  Serial.print(Input);
  Serial.println(" F");
    Serial.print("Output: ");
  Serial.print(Output);
  Serial.println();

//Button
  // read the state of the pushbutton value:
  buttonState1 = digitalRead(buttonPin1);
  buttonState2 = digitalRead(buttonPin2);



//Button Count
  if (buttonState1 == HIGH) {
      
    buttonCount = buttonCount - 1;
  } 

  if (buttonState2 == HIGH) {
      
    buttonCount = buttonCount + 1;
  } 
 
  //LCD Display
   lcd.print("Set T= ");
   lcd.print(buttonCount); 
  lcd.print(" F"); 
 lcd.setCursor(0,1); // Sets the location at which subsequent text written to the LCD will be displayed
 lcd.print("Temp = "); // Prints "Arduino" on the LCD 
  lcd.print(T); 
  lcd.print(" F");
  lcd.setCursor(0,0);  
  delay(100);
  
  Setpoint=TargetT;
  TargetT = buttonCount;



//Temp Control
if (T <= TargetT)
{
 digitalWrite(13, HIGH); //Turn LED on
digitalWrite(relay, HIGH); //Turn Heater on
}
 if (T > TargetT )
{
 digitalWrite(13, LOW); //Turn LED off
digitalWrite(relay, LOW); //Turn Heater off
}

  
Input = T;
  myPID.Compute();

  /************************************************
   * turn the output pin on/off based on pid output
   ************************************************/
  if (millis() - windowStartTime > WindowSize)
  { //time to shift the Relay Window
    windowStartTime += WindowSize;
  }
  if (Output < millis() - windowStartTime) digitalWrite(RELAY_PIN, HIGH);
  else digitalWrite(RELAY_PIN, LOW);
}