int mypin= A2;
int mypin2= 13;
int mypin3= 12;
int mypin4= 11;
float v2;
int readval;
int time = 500;
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(mypin, INPUT);
pinMode(mypin2, OUTPUT);
pinMode(mypin3, OUTPUT);
pinMode(mypin4, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
readval=analogRead(mypin);
v2=(5./1023.)*readval;
Serial.print( "the value of potentiometer is" );
Serial.println(v2);
delay(time);
if( v2<3.0){
digitalWrite(mypin4, HIGH);
}
else{
  digitalWrite(mypin4, LOW);
}
if(v2>3.0 && v2<4.0){
  digitalWrite(mypin3, HIGH);
}
else{
  digitalWrite(mypin3, LOW);
}
if( v2>4.0){
digitalWrite(mypin2, HIGH);
}
else{
  digitalWrite(mypin2, LOW);
}
}