Buzzer (pocketmage_bz)

Buzzer API

PocketmageBZ drives the PWM buzzer (10-bit LEDC channel 1 on BZ_PIN) and plays note sequences (“jingles”). Melodies are compile-time Jingle values: constexpr note arrays plus a length, so a tune costs no RAM at runtime.

Access

#include <pocketmage.h>

PocketmageBZ& bz = BZ();

BZ() is the single instance. setupBZ() runs in PocketMage_INIT() and calls begin(); the startup jingle plays automatically.

Data model

struct Note {
  int key;      // MIDI-ish note number (NOTE_* constants)
  int duration; // arbitrary ticks (see NOTE_* in the header)
};

struct Jingle {
  const Note* notes;  // PROGMEM-friendly constant array
  size_t len;
};

namespace Jingles {
  extern const Jingle Startup;    // ascending arpeggio
  extern const Jingle Shutdown;   // descending arpeggio
}

Built-in melodies use NOTE_A8 / NOTE_B8 / NOTE_C8 / NOTE_D8 constants from the include set. A custom jingle is just a new constexpr note array plus a Jingle:

constexpr static const Note myNotes[] = {
    {NOTE_A8, 120}, {NOTE_B8, 120}, {NOTE_C8, 120}, {NOTE_D8, 120}};
const Jingle myMelody = {myNotes, sizeof(myNotes) / sizeof(myNotes[0])};

Class reference

class PocketmageBZ {
public:
  PocketmageBZ();
  bool begin(int channel = 0);
  void end();
  void playJingle(const Jingle& jingle);
};

• begin(channel) attaches the buzzer to the PWM channel and is idempotent in setupBZ().
• playJingle(jingle) plays the sequence synchronously (back-to-back notes) and re-attaches the channel if it was torn down. Use MUTE_BUZZER to silence without removing calls.

PWM_CHANNEL is LEDC_CHANNEL_1, PWM_RESOLUTION is LEDC_TIMER_10_BIT.

Example

#include <pocketmage.h>

void announce() {
  BZ().playJingle(Jingles::Startup);
}