const int pinoLedVermelho = 13;
const int pinoLedAmarelo = 12;
const int pinoLedAzul = 11;
const int pinoBotaoSubir = 7;
const int pinoBotaoDescer = 6;

void setup() {
  pinMode(pinoLedVermelho, OUTPUT);
  pinMode(pinoLedAmarelo, OUTPUT);
  pinMode(pinoLedAzul, OUTPUT);
  pinMode(pinoBotaoSubir, INPUT);
  pinMode(pinoBotaoDescer, INPUT);
}



int nivel = 1;
void loop() {
  // ENTRADA
  int sinalBotaoSubir = digitalRead(pinoBotaoSubir);
  int sinalBotaoDescer = digitalRead(pinoBotaoDescer);

  // PROCESSAMENTO
  if (sinalBotaoSubir == HIGH) {
    nivel++;
    if (nivel > 3) {
      nivel = 1;
    }    
  }
  if (sinalBotaoDescer == HIGH) {
    nivel--;
    if (nivel < 1) {
      nivel = 3;
    }
  }

  // SAÍDA
  switch (nivel) {
    case 1:
    digitalWrite(pinoLedVermelho, LOW);
    digitalWrite(pinoLedAmarelo, LOW);
    digitalWrite(pinoLedAzul, HIGH);
    break;

    case 2:
    digitalWrite(pinoLedVermelho, LOW);
    digitalWrite(pinoLedAmarelo, HIGH);
    digitalWrite(pinoLedAzul, LOW);
    break;

    case 3:
    digitalWrite(pinoLedVermelho, HIGH);
    digitalWrite(pinoLedAmarelo, LOW);
    digitalWrite(pinoLedAzul, LOW);
    break;
  }

  if (sinalBotaoSubir == HIGH or sinalBotaoDescer == HIGH) {
    delay(500);
  }
}