CoreMatrix Buzzer 蜂鸣器

#include <M5Unified.h>
#include <utility/M5IOE1_Class.hpp>

static constexpr auto BUZZER_EN = m5::M5IOE1_Class::gpio2;
static constexpr auto BUZZER_PWM = m5::M5IOE1_Class::pwm_ch3;
static constexpr auto BUZZER_PWM_PIN = m5::M5IOE1_Class::gpio11;

static void drawPlaying(bool playing)
{
  M5.Display.startWrite();
  M5.Display.fillScreen(TFT_BLACK);
  M5.Display.drawRect(0, 0, 16, 16, TFT_WHITE);

  if (playing) {
    M5.Display.fillRect(3, 5, 5, 6, TFT_WHITE);
    M5.Display.drawLine(9, 6, 13, 3, TFT_WHITE);
    M5.Display.drawLine(9, 8, 14, 8, TFT_WHITE);
    M5.Display.drawLine(9, 10, 13, 13, TFT_WHITE);
  }

  M5.Display.endWrite();
  M5.Display.display();
}

static bool playTone(uint16_t frequency, uint16_t duration)
{
  auto& ioe = static_cast<m5::M5IOE1_Class&>(M5.getIOExpander(0));

  if (!ioe.setPwmFrequency(frequency) ||
      !ioe.setPwmDuty12bit(BUZZER_PWM, 2048,
                           m5::pwm_polarity_t::normal, true)) {
    return false;
  }

  drawPlaying(true);
  delay(duration);
  ioe.setPwmDuty12bit(BUZZER_PWM, 0, m5::pwm_polarity_t::normal, false);
  drawPlaying(false);
  delay(50);
  return true;
}

void setup()
{
  auto cfg = M5.config();
  cfg.serial_baudrate = 115200;
  M5.begin(cfg);

  M5.Display.setColorDepth(8);
  M5.Display.setRotation(1);
  M5.Display.setBrightness(128);

  auto& ioe = static_cast<m5::M5IOE1_Class&>(M5.getIOExpander(0));

  // M5IOE1 IO2 -> PYB_BUZZER_EN
  ioe.setHighImpedance(BUZZER_EN, false);
  ioe.setPullMode(BUZZER_EN, m5::IOExpander_Base::pull_none);
  ioe.setDirection(BUZZER_EN, true);
  ioe.digitalWrite(BUZZER_EN, true);

  // M5IOE1 IO11 -> PYB_BUZZER_PWM, PWM channel 3
  ioe.setHighImpedance(BUZZER_PWM_PIN, false);
  ioe.setDirection(BUZZER_PWM_PIN, true);
  ioe.setPwmDuty12bit(BUZZER_PWM, 0, m5::pwm_polarity_t::normal, false);

  drawPlaying(false);
  delay(20);
}

void loop()
{
  playTone(880, 500);
  playTone(990, 500);
  playTone(1120, 500);
  playTone(1180, 500);
  playTone(1320, 500);
  playTone(1480, 500);
  playTone(1650, 500);
  playTone(1760, 500);
  playTone(2731, 500);
  delay(500);
}