const int ledPin = 13;   //the number of the LED pin
const int ldrPin = A0;  //the number of the LDR pin


void setup() {

  Serial.begin(9600);
  pinMode(ledPin, OUTPUT);  //initialize the LED pin as an output
  pinMode(ldrPin, INPUT);   //initialize the LDR pin as an input
}

void loop() {

  int ldrStatus = analogRead(ldrPin);   //read the status of the LDR value

  Serial.println(ldrStatus);

  if (ldrStatus >= 400) { // if bright, turn LED on

    digitalWrite(ledPin, HIGH);               //turn LED on
    Serial.println("LED ON");
  }

  else {  //if dark turn LED off

    digitalWrite(ledPin, LOW);          //turn L ED off
    Serial.print("LED OFF");
  }
}