int LDR = A2; // LDR define
int LDR_V = 0; // holds value of LDR

void setup() {
  pinMode(LDR, INPUT); // LDR singal into board
  Serial.begin(9600); // start serial communication 
}
 
void loop() {
  LDR_V = analogRead(LDR);
  
  if (LDR_V < 490) 

   {
   Serial.print("Ambient Light level is: ");
   Serial.println(LDR_V);
   
   Serial.println("the light is... ON!");
   delay (2000);
   }
   else 
   {
   Serial.print("Ambient Light level is: ");
   Serial.println(LDR_V);
   
   Serial.println("the light is... OFF!");
   delay (2000);
   }
    
}