蜂鸣器控制器

本例程演示如何使用 librm 中的 BuzzerController 类控制蜂鸣器播放各种音乐和提示音。

BuzzerController 基于 SequencePlayer 实现，支持音符序列播放，并且提供了几条示例旋律（启动音、错误提示、成功提示等）。

代码示例

#include "tim.h"
#include "cmsis_os.h"

#include <librm.hpp>

// 自定义音乐：两只老虎（片段）
class TwoTigers : public rm::modules::BuzzerMelody {
  using Freq = rm::modules::NoteFreqStandard;
  using Duration = rm::modules::NoteDuration120;

  rm::usize note_index_{0};
  TimePoint note_start_time_;

  static constexpr std::array kMelody = {
      rm::modules::BuzzerNote(Freq::kC5, Duration::kQuarter),
      rm::modules::BuzzerNote(Freq::kD5, Duration::kQuarter),
      rm::modules::BuzzerNote(Freq::kE5, Duration::kQuarter),
      rm::modules::BuzzerNote(Freq::kC5, Duration::kQuarter),
      rm::modules::BuzzerNote(Freq::kC5, Duration::kQuarter),
      rm::modules::BuzzerNote(Freq::kD5, Duration::kQuarter),
      rm::modules::BuzzerNote(Freq::kE5, Duration::kQuarter),
      rm::modules::BuzzerNote(Freq::kC5, Duration::kQuarter),
  };

 public:
  BuzzerNote Update(TimePoint now) override {
    if (note_index_ >= kMelody.size()) {
      return BuzzerNote(0, 0);  // 播放完毕
    }

    auto note = kMelody[note_index_];
    auto elapsed = ElapsedMs(note_start_time_, now);

    if (elapsed >= note.duration) {
      note_index_++;
      note_start_time_ = now;
    }

    return note;
  }

  void Reset(TimePoint now) override {
    note_index_ = 0;
    note_start_time_ = now;
  }
};

extern "C" void BuzzerTask(const void *pv_arg) {
  // 创建蜂鸣器控制器，包含多种音乐
  rm::modules::BuzzerController<
      rm::modules::buzzer_melody::Silent,
      rm::modules::buzzer_melody::Beeps<3>,
      rm::modules::buzzer_melody::Startup,
      rm::modules::buzzer_melody::Error,
      rm::modules::buzzer_melody::Success,
      rm::modules::buzzer_melody::SuperMario,
      rm::modules::buzzer_melody::TheLick,
      TwoTigers
  > buzzer;

  // 启动 PWM
  HAL_TIM_PWM_Start(&htim4, TIM_CHANNEL_3);

  // 播放启动音
  buzzer.Play<rm::modules::buzzer_melody::Startup>();

  for (;;) {
    // 更新并获取当前音符
    auto note = buzzer.Update();

    if (note.frequency > 0) {
      // 设置频率：ARR = Timer_Clock / Frequency - 1
      uint32_t arr = 1000000 / note.frequency - 1;
      __HAL_TIM_SET_AUTORELOAD(&htim4, arr);
      __HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_3, arr / 2);  // 50% 占空比
    } else {
      // 静音
      __HAL_TIM_SET_COMPARE(&htim4, TIM_CHANNEL_3, 0);
    }

    osDelay(1);  // 1kHz 更新频率
  }
}

tip

librm 内建了几条示例旋律，可以直接使用：

• Silent - 静音
• Beeps<N> - 滴滴响 N 声
• Startup - 启动提示音
• Error - 错误提示音
• Success - 成功提示音
• SuperMario - 超级马里奥主题曲（片段）
• TheLick - The Lick（爵士经典乐句）
• SeeUAgain - See You Again（片段）