// Temperature and Humidity Monitoring System
// Green LED on when temp < 24°C
// Red LED on when temp > 26°C
// Buzzer sounds when humidity > 90%

#include <DHT.h>

// Pin definitions - CORRECTED for your diagram
#define DHTPIN 33           // DHT22 data pin connected to GPIO33 (from your diagram)
#define GREEN_LED 2         // Green LED on GPIO2 (from your diagram)
#define RED_LED 27          // Red LED on GPIO27 (from your diagram)
#define BUZZER_PIN 4        // You'll need to add a buzzer on GPIO4

// DHT sensor type
#define DHTTYPE DHT22       // Using DHT22 (not DHT11)

// Initialize DHT sensor
DHT dht(DHTPIN, DHTTYPE);

// Thresholds
const float TEMP_LOW_THRESHOLD = 24.0;   // Below 24°C - green LED on
const float TEMP_HIGH_THRESHOLD = 26.0;  // Above 26°C - red LED on
const float HUMIDITY_ALERT = 90.0;       // Above 90% - buzzer sounds

void setup() {
  Serial.begin(9600);
  Serial.println("Temperature & Humidity Monitor Started");
  
  // Initialize LED pins
  pinMode(GREEN_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  
  // Start with both LEDs off
  digitalWrite(GREEN_LED, LOW);
  digitalWrite(RED_LED, LOW);
  digitalWrite(BUZZER_PIN, LOW);
  
  // Initialize DHT sensor
  dht.begin();
  
  Serial.println("Thresholds:");
  Serial.print("  Green LED ON when temp < ");
  Serial.print(TEMP_LOW_THRESHOLD);
  Serial.println("°C");
  Serial.print("  Red LED ON when temp > ");
  Serial.print(TEMP_HIGH_THRESHOLD);
  Serial.println("°C");
  Serial.print("  Buzzer when humidity > ");
  Serial.print(HUMIDITY_ALERT);
  Serial.println("%");
  Serial.println("----------------------------------------");
}

void loop() {
  // Wait 2 seconds between readings
  delay(2000);
  
  // Read temperature and humidity
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();  // Read as Celsius
  
  // Check if readings are valid
  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read from DHT sensor!");
    Serial.println("Check wiring: DHT22 data pin should be on GPIO33");
    return;
  }
  
  // Print readings
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.print("°C | Humidity: ");
  Serial.print(humidity);
  Serial.println("%");
  
  // --- Temperature Control Logic ---
  if (temperature < TEMP_LOW_THRESHOLD) {
    // Below 24°C - Green LED ON, Red LED OFF
    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(RED_LED, LOW);
    Serial.println("  Status: COLD - Green LED ON");
  } 
  else if (temperature > TEMP_HIGH_THRESHOLD) {
    // Above 26°C - Red LED ON, Green LED OFF
    digitalWrite(GREEN_LED, LOW);
    digitalWrite(RED_LED, HIGH);
    Serial.println("  Status: HOT - Red LED ON");
  } 
  else {
    // Between 24-26°C - Both LEDs OFF
    digitalWrite(GREEN_LED, LOW);
    digitalWrite(RED_LED, LOW);
    Serial.println("  Status: NORMAL - Both LEDs OFF");
  }
  
  // --- Humidity Alert Logic ---
  if (humidity > HUMIDITY_ALERT) {
    // Humidity above 90% - Sound buzzer
    tone(BUZZER_PIN, 1000);  // 1kHz tone
    Serial.println("  ALERT: High humidity! Buzzer ON");
  } else {
    // Normal humidity - Buzzer OFF
    noTone(BUZZER_PIN);
  }
  
  Serial.println("----------------------------------------");
}