询问如何将 Arduino Mega 2560 ADC 采样频率设置为 40 HzEN

uint8_t lastReadingTime;

void loop()
{
  if ((uint8_t)(millis() - lastReadingTime) >= 25)
  {
    lastReadingTime = millis();
    uint16_t result = analogRead(A0);
    // now do something with the result
  }
}