int LDRpin =13;
int LEDpin =2;
int threshold =500;
  
void setup(){
  pinMode(LDRpin, INPUT);
  pinMode(LEDpin, OUTPUT);
  Serial.begin(9600);
}

void loop(){
  int LDRvalue =analogRead(LDRpin);
  Serial.println(LDRvalue);
  
  if (LDRvalue< threshold){
    digitalWrite(LEDpin, HIGH);
  }
  else{
      digitalWrite(LEDpin, LOW);

    }
  
  delay(1000);
}