#define TRIG_PIN 3
#define ECHO_PIN 2

#define LDR_PIN A0
#define LED_PIN 13

long duration;
int distance;

int ldrValue;
int ldrThreshold = 500;   // Adjust calibration value

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

  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  pinMode(LDR_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
}

int getDistance()
{
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);

  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);

  digitalWrite(TRIG_PIN, LOW);

  duration = pulseIn(ECHO_PIN, HIGH);

  distance = duration * 0.0343 / 2;

  return distance;
}

void loop()
{
  ldrValue = analogRead(LDR_PIN);
  distance = getDistance();

  Serial.print("LDR: ");
  Serial.print(ldrValue);

  Serial.print("  Distance: ");
  Serial.print(distance);
  Serial.println(" cm");


  bool isDark = ldrValue > ldrThreshold; 
  bool personDetected = distance < 30;


  if(isDark && personDetected)
  {
    digitalWrite(LED_PIN, HIGH);
  }
  else
  {
    digitalWrite(LED_PIN, LOW);
  }

  delay(100);
}