#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
#include <Wire.h>
#include <DHT.h>
#define DHTPIN 1
DHT dht( DHTPIN, DHT22); //(sensor pin,sensor type)
// this constant won't change:
//Key connections with arduino
const byte  down_key = 2;    // the pin that the pushbutton is attached to
const byte  up_key = 3;
//Led connections with arduino
const int LED_RED = 10; //Red LED
const int LED_GREEN = 11; //Green LED
//thermistor
const float BETA = 3950; // should match the Beta Coefficient of the thermistor

// Variables will change:
int RELAY1 = A1; // Heater
int RELAY2 = A2; // Fan
int Range = 3; // Temp +/- Range
int SetPoint = 30; // Default temp


int buttonPushCounter_down_key = 0;   // counter for the number of button presses
boolean ButtonState_down_key = 0;         // current state of the button
boolean lastButtonState_down_key = 0;     // previous state of the button
int buttonPushCounter_up_key = 0;   // counter for the number of button presses
boolean ButtonState_up_key = 0;         // current state of the button
boolean lastButtonState_up_key = 0;     // previous state of the button

//=================================================================
//                  SETUP
//=================================================================
void setup() {
  lcd.init();
  lcd.backlight();
  pinMode(LED_RED, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(RELAY1, OUTPUT);
  pinMode(RELAY2, OUTPUT);
  // initialize the button pin as a input:
  pinMode(down_key, INPUT_PULLUP);
  pinMode(up_key, INPUT_PULLUP);
  dht.begin();
 // timer.setInterval(2500L, sendSensor);

  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("Temp Controller");
  lcd.setCursor(0, 1); //Move coursor to second Line
  lcd.print("Version 1");
  digitalWrite(LED_GREEN, HIGH); //Green LED Off
  digitalWrite(LED_RED, LOW);    //Red LED On
  digitalWrite(RELAY1, LOW);     //Turn off Heater Relay
  digitalWrite(RELAY2, LOW);   //Turn off Fan Relay
  
  delay(2000);
  lcd.clear();
}
//=================================================================
//                  LOOP
//=================================================================
void loop() {
  static unsigned long timer = 0;
  unsigned long interval = 20;
  if (millis() - timer >= interval)
  {
    timer = millis();

    // read the pushbuttons input pin:
    ButtonState_down_key = digitalRead(down_key);
    ButtonState_up_key = digitalRead(up_key);

    // compare the ButtonState_down_key to its previous state
    if (ButtonState_down_key != lastButtonState_down_key)
    {
      // if the state has changed, increment the counter
      if (ButtonState_down_key == LOW)
      {
        // if the current state is LOW then the button went from off to on:
        buttonPushCounter_down_key++;

        if (SetPoint > 0)
        {
          SetPoint--;
        }
      }

      lastButtonState_down_key = ButtonState_down_key;
    }
    // compare the ButtonState_up_key to its previous state
    if (ButtonState_up_key != lastButtonState_up_key)
    {
      // if the state has changed, increment the counter
      if (ButtonState_up_key == LOW)
      {
        // if the current state is LOW then the button went from off to on:
        buttonPushCounter_up_key++;

        if (SetPoint < 100)
        {
          SetPoint++;
        }
      }

      lastButtonState_up_key = ButtonState_up_key;
    }
  }
  //Display Set point on LCD
  float t = dht.readTemperature();
  lcd.setCursor(0, 0);
  lcd.print("Temperature:");    //Do not display entered keys
  lcd.print(t);


  lcd.setCursor(0, 1);
  lcd.print("Set Point:");
  lcd.print(SetPoint);
  lcd.print("C   ");
  

  delay(100); //Update at every 100mSeconds
}
void sendSensor(){
   float h = dht.readHumidity();
  float t = dht.readTemperature();

  


  //Check Temperature is in limit
  if (t == SetPoint)
  {
    digitalWrite(RELAY1, LOW);   //Turn off heater
    digitalWrite(LED_RED, LOW);   //Turn off Red LED
    digitalWrite(LED_GREEN, HIGH); //Turn on Green LED
  }
  // If temp is over limit turn on fan /Turn off heater
  if (t > (SetPoint + Range))
  {
    digitalWrite(RELAY1, LOW);   //Turn off heater
     Serial.print("heater off");
    digitalWrite(RELAY2, HIGH);   //Turn on fan
    digitalWrite(LED_RED, LOW);   //Turn off Red LED
    digitalWrite(LED_GREEN, HIGH); //Turn on Green LED
  }
  //if temp is below limt turn on heater / turn off fan
  if (t< (SetPoint - Range) || t < SetPoint)
  {

    digitalWrite(RELAY1, HIGH);   //Turn on heater
    Serial.print("heater on");
    digitalWrite(RELAY2, LOW);   //Turn off fan
    digitalWrite(LED_GREEN, LOW); //Turn off Green LED
    digitalWrite(LED_RED, HIGH); //Turn on RED LED
  }
}