#include <DHT.h>
#include <LiquidCrystal_I2C.h>
#include <Servo.h>

#define DHTPIN 2    
#define RELAY_PIN 8  
#define POT_PIN A0    
#define SERVO_PIN 9  

#define DHTTYPE DHT22 
DHT dht(DHTPIN, DHTTYPE);

LiquidCrystal_I2C lcd(0x27, 16, 2); 

Servo myServo;

float setPoint;
float currentTemp;
float hysteresis = 2.0; 

bool relayStatus = false; // To track relay and servo state

void setup() {
  lcd.begin(16, 2);
  lcd.backlight(); 
  dht.begin();
  pinMode(RELAY_PIN, OUTPUT);
  myServo.attach(SERVO_PIN); 
  Serial.begin(9600); 
}

void loop() {
  // Read temperature from DHT22 sensor
  currentTemp = dht.readTemperature();
  
  // Read potentiometer value and map it to temperature range
  setPoint = map(analogRead(POT_PIN), 0, 1023, 0, 50); 
  
  // Apply hysteresis logic
  if (currentTemp > setPoint + (hysteresis / 2) && !relayStatus) {
    digitalWrite(RELAY_PIN, HIGH);  // Turn relay ON
    myServo.write(0);             // Move servo to 180°
    relayStatus = true;             // Update status to ON
  } 
  else if (currentTemp < setPoint - (hysteresis / 2) && relayStatus) {
    digitalWrite(RELAY_PIN, LOW);   // Turn relay OFF
    myServo.write(180);               // Move servo to 0°
    relayStatus = false;            // Update status to OFF
  }

  // Display setPoint and currentTemp on LCD
  lcd.setCursor(0, 0);
  lcd.print("Set: ");
  lcd.print(setPoint);
  lcd.print(" C");

  lcd.setCursor(0, 1);
  lcd.print("Cur: ");
  lcd.print(currentTemp);
  lcd.print(" C  "); // Extra spaces to clear old text if any
  
  // Output values to Serial Monitor for debugging
  Serial.print("SetPoint: ");
  Serial.print(setPoint);
  Serial.print(" C, ");
  Serial.print("Current: ");
  Serial.print(currentTemp);
  Serial.print(" C, ");
  Serial.print("Relay Status: ");
  Serial.println(relayStatus ? "ON" : "OFF");

  delay(2000); // Delay to allow time for readings and display
}