int LED1 = 5;
int LED2 = 6;
int LED3 = 7;
int Value ;

void setup() {
  // put your setup code here, to run once:
pinMode(LED1, OUTPUT );
pinMode(LED2, OUTPUT );
pinMode(LED3, OUTPUT );
pinMode(A0, INPUT);
Serial.begin(9600);

}

void loop() {
  // put your main code here, to run repeatedly:
  Value=analogRead(A0);
  Serial.println(Value);

  if (Value <=500){
digitalWrite(LED1, HIGH);
delay(1000);
digitalWrite(LED1, LOW);
delay(1000);
  }
  else if (Value <=800){
digitalWrite(LED2, HIGH);
delay(1000);
digitalWrite(LED2, LOW);
delay(1000);
  }
  else{
digitalWrite(LED3, HIGH);
delay(1000);
digitalWrite(LED3, LOW);
delay(1000);
  }
}