//---------------------------------------------------
// ที่มาของโค้ด
// https://youtu.be/YX4HR5XUMhQ?si=NFe4lgsHegDXUXuM
//---------------------------------------------------

const int speakerPin = 9;    

// ------------------------------------------------------------------------
byte beat = 120;  
unsigned int speed = (60000 / beat) / 4;

// ------------------------------------------------------------------------
char noteNames[] = { 'g', 'a', 'b', 'C', 'D', 'E', 'F', 'G', 'A', 'B', ' ' };
unsigned int frequencies[] = { 196, 220, 246, 262, 294, 330, 349, 392, 440, 494, 0 };
const byte noteCount = sizeof(noteNames);

//-------------------------------------------------------------------------
// Cherry Pink And Apple Blossom White
char score[] =
  "gCEGFEF"   "EDFF"
  "GABAGFE"   "G"
  "gCEGFEF"   "EDAA"
  "GEDC"
;
const byte scorelength = sizeof(score);  
byte beats[scorelength] = {
  2, 2, 2, 2, 2, 2, 2,      4, 2, 2, 8,
  2, 2, 2, 2, 2, 2, 2,      8,
  2, 2, 2, 2, 2, 2, 2,      4, 2, 2, 8,
  4, 4, 4, 8
};

// ------------------------------------------------------------------------

void setup() {
  pinMode(speakerPin, OUTPUT);  
  delay(100);
}

// ------------------------------------------------------------------------

void loop() {

  for (int i = 0; i < scorelength; i++) {  
    int duration = beats[i] * speed;  
    playNote(score[i], duration);  
  }
  delay(4000);  
}

// ------------------------------------------------------------------------

void playNote(char note, int duration) {
  // ฟังก์ชันสำหรับเล่นโน้ตตัวเดียว

  for (int i = 0; i < noteCount; i++) {  
    if (noteNames[i] == note) {  
      if (frequencies[i] > 0) {  
        tone(speakerPin, frequencies[i], duration);  
      }
    }
  }
  delay(duration);  
}