#include "DHT.h"

#define DHTPIN 4
#define DHTTYPE DHT22
#define MQ135_PIN 34
#define RELAY_PIN 26

DHT dht(DHTPIN, DHTTYPE);

// Thresholds (adjust in Wokwi)
float TEMP_LIMIT = 30.0;   // Celsius
int GAS_LIMIT = 2000;      // ADC value (0–4095)

void setup() {
  Serial.begin(115200);

  pinMode(RELAY_PIN, OUTPUT);
  digitalWrite(RELAY_PIN, LOW);   // Relay OFF initially

  dht.begin();

  Serial.println("ESP32 Wokwi Simulation Started");
}

void loop() {

  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();
  int gasValue = analogRead(MQ135_PIN);

  if (isnan(temperature) || isnan(humidity)) {
    Serial.println("DHT Sensor Error!");
    delay(2000);
    return;
  }

  Serial.println("------ SENSOR VALUES ------");
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" °C");

  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.println(" %");

  Serial.print("Gas Value: ");
  Serial.println(gasValue);

  // Relay Logic (Peltier + Fan)
  if (temperature > TEMP_LIMIT || gasValue > GAS_LIMIT) {
    digitalWrite(RELAY_PIN, HIGH);
    Serial.println("Relay ON (Cooling / Ventilation ON)");
  } else {
    digitalWrite(RELAY_PIN, LOW);
    Serial.println("Relay OFF");
  }

  Serial.println("----------------------------\n");
  delay(2000);
}