# define ldr 15  
# define relay  2
#define led 16
int level;
void setup() {
  pinMode(relay, OUTPUT);
  pinMode(led, OUTPUT);  
  digitalWrite(relay, LOW); 
  Serial.begin(9600);       
}

void loop() {
  level = analogRead(ldr);  
  Serial.println(level);       
  
  if (level < 2500) {
    digitalWrite(relay, HIGH);
    digitalWrite(led,HIGH) ;
  } else {
    digitalWrite(relay, LOW);
    digitalWrite(led,LOW);  
  }
  
  delay(1000);
}