5.4.7 Project 4.1 Play Happy Birthday

1. Description

There is a audio power amplifier element in the car expansion board, which is as an external amplification equipment to play music.

In this project, we will work to play a piece of music by using it.

2. Component Knowledge

Passive Buzzer: The audio power amplifier (like the passive buzzer) does not have internal oscillation. When controlling, we need to input square waves of different frequencies to the positive pole of the component and ground the negative pole to control the power amplifier to chime sounds of different frequencies.

3. Control Pin

Passive Buzzer	25
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4. Test Code

#include <BuzzerESP32.h>

BuzzerESP32 buzzer(25); // Initialize buzzer on GPIO25

void setup()
{
  buzzer.setTimbre(30); // Set timbre (sound quality)
  birthday();          // Play birthday melody
}

void loop()
{
  // Empty loop as melody plays only once at startup
}

void birthday()
{
  // Play birthday melody - parameters are (frequency, duration)
  buzzer.playTone(294, 250);  // D4
  buzzer.playTone(440, 250);  // A4
  buzzer.playTone(392, 250);  // G4
  buzzer.playTone(532, 250);  // C5 (slightly sharp)
  buzzer.playTone(494, 250);  // B4
  buzzer.playTone(392, 250);  // G4
  buzzer.playTone(440, 250);  // A4
  buzzer.playTone(392, 250);  // G4
  buzzer.playTone(587, 250);  // D5
  buzzer.playTone(532, 250);  // C5 (slightly sharp)
  buzzer.playTone(392, 250);  // G4
  buzzer.playTone(784, 250);  // G5
  buzzer.playTone(659, 250);  // E5
  buzzer.playTone(532, 250);  // C5 (slightly sharp)
  buzzer.playTone(494, 250);  // B4
  buzzer.playTone(440, 250);  // A4
  buzzer.playTone(698, 250);  // F5
  buzzer.playTone(659, 250);  // E5
  buzzer.playTone(532, 250);  // C5 (slightly sharp)
  buzzer.playTone(587, 250);  // D5
  buzzer.playTone(532, 500);  // C5 (slightly sharp) - longer duration
  buzzer.playTone(0, 0);      // Turn off buzzer
}

5. Test Result

The passive buzzer will play happy Birthday.