const int led_0 = A0;
const int led_1 = A1;
const int led_2 = A2;
const int led_3 = A3;
const int led_4 = A4;
const int pot = A5;

void setup() {
  pinMode(led_0, OUTPUT);
  pinMode(led_1, OUTPUT);
  pinMode(led_2, OUTPUT);
  pinMode(led_3, OUTPUT);
  pinMode(led_4, OUTPUT);
  pinMode(pot, INPUT);

  Serial.begin(9600);
}

void loop() {
  int pot_val = map(analogRead(pot), 0, 1024, 0, 100);
  Serial.println(pot_val);

  if (pot_val >= 0 && pot_val < 20) {
    digitalWrite(led_0, HIGH);
    digitalWrite(led_1,  LOW);
    digitalWrite(led_2,  LOW);
    digitalWrite(led_3,  LOW);
    digitalWrite(led_4,  LOW);
  } 
  else if (pot_val >= 20 && pot_val < 40) {
    digitalWrite(led_0, HIGH);
    digitalWrite(led_1, HIGH);
    digitalWrite(led_2,  LOW);
    digitalWrite(led_3,  LOW);
    digitalWrite(led_4,  LOW);
  }
  else if (pot_val >= 40 && pot_val < 60) {
    digitalWrite(led_0, HIGH);
    digitalWrite(led_1, HIGH);
    digitalWrite(led_2, HIGH);
    digitalWrite(led_3,  LOW);
    digitalWrite(led_4,  LOW);
  }
  else if (pot_val >= 60 && pot_val < 80) {
    digitalWrite(led_0, HIGH);
    digitalWrite(led_1, HIGH);
    digitalWrite(led_2, HIGH);
    digitalWrite(led_3, HIGH);
    digitalWrite(led_4,  LOW);
  }
  else {
    digitalWrite(led_0, HIGH);
    digitalWrite(led_1, HIGH);
    digitalWrite(led_2, HIGH);
    digitalWrite(led_3, HIGH);
    digitalWrite(led_4, HIGH);
  }

  delay(30);
}