int myPin=A2;
int readVal;
int redPin=2;
int yellowPin=4;
int greenPin=7;
float V2;
int dt=250;
void setup() {
  // put your setup code here, to run once:
  
Serial.begin (9600);
pinMode(myPin,INPUT);
pinMode(redPin,OUTPUT);
pinMode(yellowPin,OUTPUT);
pinMode(greenPin,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  
readVal=analogRead(myPin);
  V2=(5./1023.)*readVal;
  Serial.print("potensiometer Voltage is ");
  Serial.println(V2);
  if(V2<3){
    digitalWrite(greenPin,HIGH);
    digitalWrite(yellowPin,LOW);
    digitalWrite(redPin,LOW);

  }
  if(V2<4 && V2>3){
    digitalWrite(greenPin,LOW);
    digitalWrite(yellowPin,HIGH);
    digitalWrite(redPin,LOW);
    
  }
  if(V2>4){
    digitalWrite(greenPin,LOW);
    digitalWrite(yellowPin,LOW);
    digitalWrite(redPin,HIGH);
  }
  delay(dt);
}