int ldr=A1;
int led=3;
int ldr_val;
void setup() {
  pinMode(led,OUTPUT);
  Serial.begin(9600);
  // put your setup code here, to run once:

}

void loop() {
  ldr_val=analogRead(ldr);
  Serial.print("Value of sensor :");
  Serial.println(ldr_val);
  delay(1000);
  if(ldr_val>800)
  {
    digitalWrite(led,HIGH);
  }
  else
  {
    digitalWrite(led,LOW);
  }
  // put your main code here, to run repeatedly:

}