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

#define DHTPIN 2    
#define DHTTYPE DHT22   
DHT dht(DHTPIN, DHTTYPE);

#define RELAY_PIN 10

LiquidCrystal_I2C lcd(0x27, 16, 2);  

const byte ROWS = 4; 
const byte COLS = 4; 
char keys[ROWS][COLS] = {
  {'1','2','3', 'A'},
  {'4','5','6', 'B'},
  {'7','8','9', 'C'},
  {'*','0','#', 'D'}
};
byte rowPins[ROWS] = {9, 8, 7, 6};
byte colPins[COLS] = {5, 4, 3, 11}; 

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

float tempSetpoint = 25.0; 
float humiditySetpoint = 50.0; 



void setup() {
  pinMode(RELAY_PIN, OUTPUT);
  dht.begin();
  delay(2000);
  Serial.begin(9600);
  Serial.println("DHTxx test!");
  lcd.init(); 
  lcd.backlight();
  lcd.begin(16, 2); 
   updateLCD("Initializing...", "Please wait...");
}


void loop() {
  
  delay(2000);
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  Serial.print("Humidity: ");
  Serial.print(h);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(t);
  Serial.println(" *C");

  if (isnan(h) || isnan(t) ) {
    updateLCD("Sensor error", "");
    return;
  } else {
     updateLCD("Temp: " + String(t) + "C", "Humidity: " + String(h) + "%");
    delay(200);
  }


  

  char key = keypad.getKey();
  while (key == NO_KEY) {
    updateLCD("Press Keypad", " ");
    key = keypad.getKey();
    delay(200); // Small delay to prevent overwhelming the CPU
  }

    if (key) {
        switch (key) {
            case 'A':
                digitalWrite(RELAY_PIN, HIGH);
                updateLCD("Fan turned ON", " ");
                Serial.print("Fan turned ON");
                break;
            case 'B':
                digitalWrite(RELAY_PIN, LOW);
                updateLCD("Fan turned OFF", " ");
                Serial.print("Fan turned OFF");
                break;
            case 'C':
                humiditySetpoint = 30.0;
                updateLCD("Humidity", "setpoint 30%");
                break;
            case 'D':
                humiditySetpoint = 40.0;
                updateLCD("Humidity", "setpoint 40%");
                break;
            case '*':
                humiditySetpoint = 50.0;
                updateLCD("Humidity", "setpoint 50%");
                break;
            case '#':
                humiditySetpoint = 60.0;
                updateLCD("Humidity", "setpoint 60%");
                break;
            default:
                for (char numKey = '0'; numKey <= '9'; numKey++) {
                    if (key == numKey) {
                        tempSetpoint = (key - '0') * 10;
                        updateLCD("Temp setpoint:", ":" + String(tempSetpoint) + "C");
                        break;
                    }
                }
        }

      delay(200); 
      if (t >= tempSetpoint || h >= humiditySetpoint) {
        digitalWrite(RELAY_PIN, HIGH); // Turn on the fan
        Serial.print("Fan turned ON");
        } else {
        digitalWrite(RELAY_PIN, LOW); // Turn off the fan
        Serial.print("Fan turned OFF");
        }
      }

}

void updateLCD(String line1, String line2) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(line1);
  lcd.setCursor(0, 1);
  lcd.print(line2);
}