2.2 Musical Melody Player

Now let’s turn our Pico into a music player! We’ll switch from an active buzzer to a passive buzzer - the difference is like switching from a car horn to a piano.

Active vs Passive Buzzer: - Active buzzer: Fixed tone, just beeps (like a smoke alarm) - Passive buzzer: Variable frequency, can play musical notes (like a speaker)

With a passive buzzer, we can control the frequency to create Do-Re-Mi-Fa-Sol-La-Ti notes and play actual melodies! Time to make some music! ♫

Component List

• Raspberry Pi Pico W x1

• 830 Tie-Points Breadboard x1

• Transistor S8050 x1

• Resistor 1KΩ x1

• Passive Buzzer x1

• Jumper Wire Several

Component knowledge

transistor

Buzzer

How musical tone generation works:

Frequency Control: - Different frequencies = different musical notes (262Hz = C4, 440Hz = A4, etc.) - Arduino’s tone() function generates precise frequencies - noteDurations[] controls how long each note plays

Power Amplification: The transistor boosts the signal for clearer, louder music - like adding an amplifier to a guitar!

Connect

Two buzzers are included in the kit, we use a passive buzzer (one with an exposed PCB on the back).

The buzzer needs a transistor to work, here we use S8050.

Code

Note

• Open the 2.2_musical_melody_player.ino file under the path of Ultimate-Starter-Kit-for-Pico-W\Arduino\1.Project or copy this code into Thonny, then click “Run Current Script” or simply press F5 to run it.

• Or copy this code into Arduino IDE.

• Don’t forget to select the board(Raspberry Pi Pico) and the correct port before clicking the Upload button.

After running the code, enjoy the classic “Twinkle Twinkle Little Star” melody! ✨ The serial monitor shows each note being played with its frequency (Hz). The melody repeats every few seconds, and you can see the musical progression: Do-Do-Sol-Sol-La-La-Sol… It’s like having a tiny digital music box!

The following is the program code:

/*
  Musical Melody Player

  Plays "Twinkle Twinkle Little Star" melody using
  tone generation on a buzzer or speaker.
*/

// Musical note frequencies (in Hz)
const int NOTE_C4 = 262;    // Do
const int NOTE_D4 = 294;    // Re
const int NOTE_E4 = 330;    // Mi
const int NOTE_F4 = 349;    // Fa
const int NOTE_G4 = 392;    // Sol
const int NOTE_A4 = 440;    // La
const int NOTE_B4 = 494;    // Ti
const int NOTE_C5 = 523;    // Do (high)

// Pin and timing constants
const int BUZZER_PIN = 15;          // buzzer connected to pin 15
const int MELODY_LENGTH = 14;       // number of notes in melody
const int REPEAT_DELAY = 2000;      // delay before repeating melody

// "Twinkle Twinkle Little Star" melody
int melody[MELODY_LENGTH] = {
  NOTE_C4, NOTE_C4, NOTE_G4, NOTE_G4,  // Twin-kle twin-kle
  NOTE_A4, NOTE_A4, NOTE_G4,           // lit-tle star
  NOTE_F4, NOTE_F4, NOTE_E4, NOTE_E4,  // How I won-der
  NOTE_D4, NOTE_D4, NOTE_C4            // what you are
};

// Note durations (4 = quarter note, 8 = eighth note, 2 = half note)
int noteDurations[MELODY_LENGTH] = {
  4, 4, 4, 4,  // quarter notes
  4, 4, 2,     // quarter, quarter, half
  4, 4, 4, 4,  // quarter notes
  4, 4, 2      // quarter, quarter, half
};

void setup() {
  // Initialize serial communication
  Serial.begin(115200);
  Serial.println("=== Musical Melody Player ===");
  Serial.println("Playing: Twinkle Twinkle Little Star");
  Serial.println();

  // Play the melody once on startup
  playMelody();
}

void loop() {
  // Wait and then repeat the melody
  Serial.println("Playing melody again...");
  delay(REPEAT_DELAY);
  playMelody();
}

// Function to play the complete melody
void playMelody() {
  Serial.println("♪ Now playing: Twinkle Twinkle Little Star ♪");

  // Play each note in the melody
  for (int noteIndex = 0; noteIndex < MELODY_LENGTH; noteIndex++) {
    // Calculate note duration
    int noteDuration = 1000 / noteDurations[noteIndex];

    // Play the note
    tone(BUZZER_PIN, melody[noteIndex], noteDuration);

    // Show current note being played
    Serial.print("Note ");
    Serial.print(noteIndex + 1);
    Serial.print("/");
    Serial.print(MELODY_LENGTH);
    Serial.print(": ");
    Serial.print(melody[noteIndex]);
    Serial.println("Hz");

    // Pause between notes (note duration + 30% for clear separation)
    int pauseBetweenNotes = noteDuration * 1.30;
    delay(pauseBetweenNotes);

    // Stop the tone
    noTone(BUZZER_PIN);
  }

  Serial.println("Melody complete!");
  Serial.println();
}

Phenomenon