const int LDR_PIN = A0;           // LDR connected to analog pin A0
const int TRIGGER_PIN = 7;        // Ultrasonic sensor trigger pin
const int ECHO_PIN = 6;           // Ultrasonic sensor echo pin

void setup() {
  Serial.begin(9600);
}

void loop() {
  int dataArray[] = {1, 2, 3};

  for (int i = 0; i < 3; i++) {
    if (dataArray[i] == 1) {
      int ldrValue = readLDR();
      if (ldrValue < 200) {
        Serial.println("Light intensity is low");
      }
    } else if (dataArray[i] == 2) {
      int distance = readUltrasonic();
      if (distance < 20) {
        Serial.println("Distance is near");
      }
    } else if (dataArray[i] == 3) {
      Serial.println("Done");
    }
    delay(1000); // Delay before reading the next sensor
  }
}

int readLDR() {
  int ldrValue = analogRead(LDR_PIN);
  return ldrValue;
}

int readUltrasonic() {
  // Send ultrasonic signal
  pinMode(TRIGGER_PIN, OUTPUT);
  digitalWrite(TRIGGER_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGGER_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN, LOW);

  // Receive ultrasonic echo
  pinMode(ECHO_PIN, INPUT);
  long duration = pulseIn(ECHO_PIN, HIGH);

  // Convert duration to distance
  int distance = duration * 0.034 / 2;  // Speed of sound is 34 cm/ms

  return distance;
}