#define ledPin 13      // the pin that the LED is attached to
int incomingByte;      // a variable to read incoming serial data into
int speakerOut = 9;
int DEBUG = 0;
void setup() {
  // initialize serial communication:
  Serial.begin(9600);
  // initialize the LED pin as an output:
  pinMode(ledPin, OUTPUT);
  pinMode(speakerOut, OUTPUT);
  if (DEBUG) { 
    Serial.begin(9600); // Set serial out if we want debugging
  } 
}

#define  do_ 3830    // 261 Hz 
#define  re    3400    // 294 Hz 
#define  mi    3038    // 329 Hz 
#define  fa    2864    // 349 Hz 
#define  sol    2550    // 392 Hz 
#define  la    2272    // 440 Hz 
#define  si    2028    // 493 Hz 
#define  DO    1912    // 523 Hz 

#define P 200
#define I 300
#define U 400

#define  R     0

int melody[] = {P, I, U, P, I, U, P, I, U, P, I, U};
int beats[] = {4, 8, 4, 16, 4, 8, 4, 8, 4, 16, 4, 8};
//int melody[] = {  sol, sol, DO, DO, la, sol, si, si, la, sol, si, si, la, sol, DO, mi, mi, sol, mi, sol, mi, re, re, fa, fa, mi, mi, re, re, do_};
//int beats[]  = { 32, 32, 32,  32,  32,  32, 32, 32,  32, 32, 32,  32,  32,  32, 64, 32,  32, 32, 32,  32,  32,  32, 32, 32, 32, 32, 32, 32, 32, 32 }; 
int MAX_COUNT = sizeof(melody) / 2; // Melody length, for looping.

long tempo = 10000;
int pause = 1000;
int rest_count = 100;

int tone = 0;
int beat = 0;
long duration  = 0;

void playTone() {
  long elapsed_time = 0;
  if (tone > 0) { 
    while (elapsed_time < duration) {

      digitalWrite(speakerOut,HIGH);
      delayMicroseconds(tone / 2);

      digitalWrite(speakerOut, LOW);
      delayMicroseconds(tone / 2);
      
      elapsed_time += (tone);
    } 
  }
  else { // Rest beat; loop times delay
    for (int j = 0; j < rest_count; j++) { // See NOTE on rest_count
      delayMicroseconds(duration);  
    }                                
  }
}

void loop() {
  // see if there's incoming serial data:
  if (Serial.available() > 0) {
    // read the oldest byte in the serial buffer:
    incomingByte = Serial.read();
    // if it's a capital H (ASCII 72), turn on the LED:
    if (incomingByte == 'H') {
       
      //toca a melodia
      digitalWrite(ledPin, HIGH);
            delay(110);
      digitalWrite(ledPin, LOW);
            delay(40);
      digitalWrite(ledPin, HIGH);
            delay(110);
      digitalWrite(ledPin, LOW);
            delay(80);
      digitalWrite(ledPin, HIGH);
            delay(200);
      digitalWrite(ledPin, LOW);
   
      for (int i=0; i<MAX_COUNT; i++) 
      {
         tone = melody[i];
         beat = beats[i];
         duration = beat * tempo;
         playTone(); 
         delayMicroseconds(pause);
       }
   
       
   
    }
    // if it's an L (ASCII 76) turn off the LED:
    if (incomingByte == 'L') {
      digitalWrite(ledPin, LOW);
      digitalWrite(speakerOut, LOW);
    }
  }
}