const int ldrPin = A0; 
const int led=8;
const int buzzer=7;
void setup() {
  Serial.begin(9600);
  pinMode(ldrPin, INPUT);
  pinMode(led, OUTPUT);
  pinMode(buzzer, OUTPUT); 
}

void loop() {
  int ldrValue = analogRead(ldrPin); 
  digitalWrite(led, LOW);
  delayMicroseconds(2);
  digitalWrite(buzzer, LOW);
  delayMicroseconds(2);
  Serial.print("LDR Value: ");
  Serial.println(ldrValue);
  if(ldrValue < 300)
  {
    digitalWrite(led, HIGH); 
    delay(100);
    digitalWrite(led, LOW);
    digitalWrite(buzzer, HIGH);
  }
  delay(1000);  
}