// Playing melodies.
// Arduino tone() function - note frequencies.
// Notes:
// note   frequency
// c      262 Hz
// d      294 Hz
// e      330 Hz
// f      349 Hz
// g      392 Hz
// a      440 Hz
// b      494 Hz
// C      523 Hz

const int buzzerPin = 9;
// The length is the sum of the notes and pauses
const int songLength = 18;
// characters are notes and space is a pause
char notes[] = "cdfda ag cdfdg gf "; 

// Setting up the rhythm.
int beats[] = {1,1,1,1,1,1,4,4,2,1,1,1,1,1,1,4,4,2};

// "tempo" melody speed. The smaller the tempo, the faster the speed.
int tempo = 150;

void setup() 
{
  pinMode(buzzerPin, OUTPUT);
}

void loop() 
{
  int i, duration;
  for (i = 0; i < songLength; i++)
  {
    duration = beats[i] * tempo;
    // if there is no note
    if (notes[i] == ' ')
    {
      delay(duration);          
    }
    else                         
    {
      tone(buzzerPin, frequency(notes[i]), duration);
      delay(duration);          
    }
    // short pause between notes
    delay(tempo / 10);
  }
  // stop the loop once the song is played
  while(true){}
}

int frequency(char note) 
{
  int i;
  // number of notes
  const int numNotes = 8;
  char names[] = { 'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C' };
  int frequencies[] = {262, 294, 330, 349, 392, 440, 494, 523};
  
  // if the note exists, return its frequency
  for (i = 0; i < numNotes; i++)  
  {
    if (names[i] == note)       
    {
      return(frequencies[i]);    
    }
  }
  return(0); 
}

#include <LiquidCrystal.h>

LiquidCrystal lcd(11, 12, 2, 3, 4, 5);
const int buttonPin = 7;
const int buzzerPin = 9;

// the "Happy Birthday" melody and note durations
#define NOTE_C4 262
#define NOTE_D4 294
#define NOTE_E4 330
#define NOTE_F4 349
#define NOTE_G4 392
#define NOTE_A4 440
#define NOTE_AS4 466
#define NOTE_C5 523

int happyBirthdayM[] = {
  NOTE_C4, NOTE_C4, NOTE_D4, NOTE_C4, NOTE_F4, NOTE_E4, // "Happy Birthday to You"
  NOTE_C4, NOTE_C4, NOTE_D4, NOTE_C4, NOTE_G4, NOTE_F4, // --*--
  NOTE_C4, NOTE_C4, NOTE_C5, NOTE_A4, NOTE_F4, NOTE_E4, NOTE_D4, // "Happy Birthday dear [Name]"
  NOTE_AS4, NOTE_AS4, NOTE_A4, NOTE_F4, NOTE_G4, NOTE_F4 // --*--
};
int happyBirthdayND[] = {
  4, 4, 4, 4, 4, 2, 4, 4, 4, 4, 4, 2, 4, 4, 4, 4, 4, 4, 2, 4, 4, 4, 4, 4, 2
};

// the "Jingle Bells" melody and note durations
int JingleBellsM[] = {
  NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_G4, NOTE_C4, NOTE_D4, NOTE_E4,
  NOTE_F4, NOTE_F4, NOTE_F4, NOTE_F4, NOTE_F4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_E4, NOTE_D4, NOTE_D4, NOTE_E4, NOTE_D4, NOTE_G4
};
int JingleBellsND[] = {
  8, 8, 4, 8, 8, 4, 8, 8, 8, 8, 2, 8, 8, 8, 8, 4, 8, 8, 8, 8, 4, 8, 8, 8, 2
};

// the melodies into arrays
int* melodyArray[] = { 
  happyBirthdayM, JingleBellsM,
};
int* noteDurations[] = {
  happyBirthdayND, JingleBellsND,
};

// names of the melodies
const char* melodyNames[] = {
  "Happy Birthday",
  "Jingle Bells"
};

void setup() {
  lcd.begin(16, 2);
  pinMode(buttonPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  Serial.begin(9600);

  // display the initial melody name on the LCD
  lcd.setCursor(0, 0);
  lcd.print(melodyNames[0]);
}

void loop() {
  static int cur_element = 0;
  static bool buttonPressed = false;
  
  // read button state
  int btnState = digitalRead(buttonPin);
  
  // button press
  if (btnState == HIGH && !buttonPressed) {
    buttonPressed = true;
    
    // move to the next melody
    cur_element = playNextMelody(cur_element);
    
    // display the name of the melody on the LCD
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print(melodyNames[cur_element]);

    // play the selected melody
    play(melodyArray[cur_element], noteDurations[cur_element], (cur_element == 0) ? sizeof(happyBirthdayM) / sizeof(happyBirthdayM[0]) : sizeof(JingleBellsM) / sizeof(JingleBellsM[0]));
  } else if (btnState == LOW) {
    buttonPressed = false;
  }
}

int playNextMelody(int cur_element) {
  cur_element++;
  if (cur_element >= 2) {
    cur_element = 0;
  }
  return cur_element;
}

void play(int melody[], int noteDurations[], int size) {
  // iterate over the notes of the melody
  for (int thisNote = 0; thisNote < size; thisNote++) {
    // calculate the note duration
    int noteDuration = 1000 / noteDurations[thisNote];
    tone(buzzerPin, melody[thisNote], noteDuration);

    // set a minimum time between notes
    int pauseBetweenNotes = noteDuration * 1.30;
    delay(pauseBetweenNotes);

    // stop the tone playing
    noTone(buzzerPin);
  }
}