処理時間を計測する

[ShotaAk]

計測方法

  auto start_time = micros();
  M5.update();
  M5_LOGI("elapsed time [us]:%d", micros() - start_time);

[ShotaAk]

M5.update() : 約 11.5 usec

  auto start_time = micros();
  M5.update();
  M5_LOGI("elapsed time [us]:%d", micros() - start_time);

[ShotaAk]

コマンド受信（データがないとき）： 58 ~ 68 usec

  auto start_time = micros();
  if(g_receiver.receive()) {
    // M5_LOGD("Received command!");
  }
  M5_LOGI("elapsed time:%d", micros() - start_time);

[ShotaAk]

I2Cのデータ送信（100kHz）：819 ~ 827 usec

  auto start_time = micros();
  const unsigned char SLAVE_ADDR = 0x54;
  Wire1.beginTransmission(SLAVE_ADDR);
  Wire1.write(send_data, DATA_SIZE);
  
  if(Wire1.endTransmission() == 0) {
    // M5_LOGI("Sent command!");
  } else {
    M5_LOGD("Failed to send command!");
  }
  M5_LOGI("elapsed time:%d", micros() - start_time);

[ShotaAk]

loop関数：880 ~ 910 usec

i2cのクロックを400kHzに変更後：350 ~ 360 usec

unsigned long start_time = 0;
void loop() {
  M5_LOGI("elapsed time:%d", micros() - start_time);
  start_time = micros();

[ShotaAk]

I2Cのデータ送信（400kHz）：270 ~ 273 usec

  Wire1.begin(M5.In_I2C.getSDA(), M5.In_I2C.getSCL(), 400000);

  auto start_time = micros();
  const unsigned char SLAVE_ADDR = 0x54;
  Wire1.beginTransmission(SLAVE_ADDR);
  Wire1.write(send_data, DATA_SIZE);
  
  if(Wire1.endTransmission() == 0) {
    // M5_LOGI("Sent command!");
  } else {
    M5_LOGD("Failed to send command!");
  }
  M5_LOGI("elapsed time:%d", micros() - start_time);