#define LIGHT_PIN A0
  #define LED_PIN 13

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

void loop() {
  // put your main code here, to run repeatedly:
  int lightLevel = analogRead(LIGHT_PIN);
  Serial.println(lightLevel);
// if the Light level was low enough, the light turn on
  if(lightLevel > 900)
  {
    digitalWrite(LED_PIN, HIGH);
  }
// Else the light level high enoung, the light turn of 
  else {
    digitalWrite(LED_PIN, LOW);
  }

}