int ldrPin = A0;
int ledPin = 11;

void setup() {
  // put your setup code here, to run once:
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  int ldrValue = analogRead(ldrPin);
  Serial.print("value : ");
  Serial.println(ldrValue);
  delay(1000);

  if(ldrValue > 500) {
    digitalWrite(ledPin, HIGH);
    Serial.println("led status : on");
  } else {
    digitalWrite(ledPin, LOW);
    Serial.println("led status : off");
  }
}