#include <LiquidCrystal.h>
#include <DHT.h>

LiquidCrystal lcd(D7, D8, D9, D10, D11, D12);

#define DHTPIN    D5
#define DHTTYPE   DHT22
DHT dht(DHTPIN, DHTTYPE);

// Sensor pins
#define TRIG_PIN  D2
#define ECHO_PIN  D3
#define GAS_PIN   A0

// LED pins
#define RED_LED   D4
#define BLUE_LED  D6
#define GREEN_LED D13

void setup() {
  lcd.begin(16, 2);
  dht.begin();

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(RED_LED, OUTPUT);
  pinMode(BLUE_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);

  digitalWrite(RED_LED, LOW);
  digitalWrite(BLUE_LED, LOW);
  digitalWrite(GREEN_LED, LOW);
}

void loop() {
  // 🔊 Distance
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  long duration = pulseIn(ECHO_PIN, HIGH);
  float distance = duration * 0.034 / 2;

  // 🌡️ DHT22
  float temp = dht.readTemperature();
  float humi = dht.readHumidity();

  // 💨 MQ2 (analogRead returns 0–1023)
  int gasRaw = analogRead(GAS_PIN);
  float gasPPM = (gasRaw / 1023.0) * 1000.0; // Rescale to ~PPM

  // 🚨 LED Alerts
  digitalWrite(RED_LED,  (distance > 100.0) ? HIGH : LOW);
  digitalWrite(BLUE_LED, (temp > 45.0 || humi > 40.0) ? HIGH : LOW);
  digitalWrite(GREEN_LED, (gasPPM > 400.0) ? HIGH : LOW);

  // 🖥 LCD Output
  lcd.setCursor(0, 0);
  lcd.print("T:");
  lcd.print(temp, 0);
  lcd.print(" H:");
  lcd.print(humi, 0);

  lcd.setCursor(0, 1);
  lcd.print("D:");
  lcd.print(distance, 0);
  lcd.print(" G:");
  lcd.print(gasPPM, 0);
  lcd.print("  "); // Clear extra

  delay(500);
}