// =========================================
// SMART EMERGENCY EVACUATION LIGHT
// ESP32 + MQ2 + MPU6050 + LED + BUZZER
// WOKWI SIMULATION CODE
// =========================================

#include <Wire.h>
#include <MPU6050.h>

MPU6050 mpu;

// ================= PIN =================
#define MQ2_PIN      34
#define LED_PIN      25
#define BUZZER_PIN   26

// ================= VARIABLE =================
int smokeValue;
long vibrationValue;

// ================= THRESHOLD =================
int smokeThreshold = 300;
long vibrationThreshold = 40000;

void setup() {

  Serial.begin(115200);

  // Pin mode
  pinMode(MQ2_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  // I2C MPU6050
  Wire.begin();

  // MPU6050 start
  mpu.initialize();

  Serial.println("Smart Emergency System Started");

  if (mpu.testConnection()) {
    Serial.println("MPU6050 Connected");
  } else {
    Serial.println("MPU6050 Connection Failed");
  }

  digitalWrite(LED_PIN, LOW);
  digitalWrite(BUZZER_PIN, LOW);
}

void loop() {

  // =========================
  // READ MQ2 SENSOR
  // =========================
  smokeValue = analogRead(MQ2_PIN);

  // =========================
  // READ MPU6050 SENSOR
  // =========================
  int16_t ax, ay, az;

  mpu.getAcceleration(&ax, &ay, &az);

  vibrationValue = abs(ax) + abs(ay) + abs(az);

  // =========================
  // SERIAL MONITOR
  // =========================
  Serial.print("Smoke Value : ");
  Serial.print(smokeValue);

  Serial.print(" | Vibration : ");
  Serial.println(vibrationValue);

  // =========================
  // EMERGENCY CONDITION
  // =========================
  if (smokeValue > smokeThreshold || vibrationValue > vibrationThreshold) {

    Serial.println("!!! EMERGENCY DETECTED !!!");

    digitalWrite(LED_PIN, HIGH);
    digitalWrite(BUZZER_PIN, HIGH);

  } else {

    digitalWrite(LED_PIN, LOW);
    digitalWrite(BUZZER_PIN, LOW);
  }

  delay(500);
}