#define POTENT_PIN A0
#define RED_LED 4
#define GREEN_LED 3
#define BLUE_LED 2

int leds[3] = { RED_LED, GREEN_LED, BLUE_LED };

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.write("Read Input Voltage from potentiometer\n");

  pinMode(RED_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);
  pinMode(BLUE_LED, OUTPUT);
  pinMode(POTENT_PIN, OUTPUT);

}

void lighUp_led(int index) {
  digitalWrite(leds[index], HIGH);
  delay(350);
  digitalWrite(leds[index], LOW);
}

void loop() {
  // put your main code here, to run repeatedly:

  int sensorValue = analogRead(POTENT_PIN); 
  double voltage = sensorValue * (3.0 / 1023.0);
  int ledIndex = map(sensorValue, 0, 1023, 0, 2);

  lighUp_led(ledIndex);

  Serial.println("\nLit up pin number");
  Serial.print(ledIndex);
}