// Frecuencias (Hz) - Cuarta octava
const int Do = 262;
const int Re = 294;
const int Mi = 330;
const int Fa = 349;
const int Sol = 392;
const int La = 440;
const int Si = 494;

// Pines de conexión
const int BOTON_do = 7;
const int BOTON_re = 6;
const int BOTON_mi = 5;
const int BOTON_fa = 4;
const int BOTON_sol = 3;
const int BOTON_la = 2;
const int BOTON_si = 1;
const int PIEZO = 13;

// Notas
int nota[] = {Do, Re, Mi, Fa, Sol, La, Si};

// Botones
int boton[] = {BOTON_do, BOTON_re, BOTON_mi, BOTON_fa, BOTON_sol, BOTON_la, BOTON_si};

void
setup() {
  for (int i = 0; i < 7; i++) {
    pinMode(boton[i], INPUT);
  }
  pinMode(PIEZO, OUTPUT);
}

void loop() {
  for (int i = 0; i < 7; i++) {
    while (digitalRead(boton[i]) == HIGH) {
      tone(PIEZO, nota[i]);
    }
  }
  noTone(PIEZO);
}