analog write.c

void analogWrite(uint32_t ulPin, uint32_t ulValue)
{
#if defined(HAL_DAC_MODULE_ENABLED) && !defined(HAL_DAC_MODULE_ONLY)
  uint8_t do_init = 0;
#endif
  PinName p = digitalPinToPinName(ulPin);
  if (p != NC) {
#if defined(HAL_DAC_MODULE_ENABLED) && !defined(HAL_DAC_MODULE_ONLY)
    if (pin_in_pinmap(p, PinMap_DAC)) {
      if (is_pin_configured(p, g_anOutputPinConfigured) == false) {
        do_init = 1;
        set_pin_configured(p, g_anOutputPinConfigured);
      }
      ulValue = mapResolution(ulValue, _writeResolution, DACC_RESOLUTION);
      dac_write_value(p, ulValue, do_init);
    } else
#endif //HAL_DAC_MODULE_ENABLED && !HAL_DAC_MODULE_ONLY
#if defined(HAL_TIM_MODULE_ENABLED) && !defined(HAL_TIM_MODULE_ONLY)
      if (pin_in_pinmap(p, PinMap_PWM)) {
        if (is_pin_configured(p, g_anOutputPinConfigured) == false) {
          set_pin_configured(p, g_anOutputPinConfigured);
        }
        ulValue = mapResolution(ulValue, _writeResolution, _internalWriteResolution);
        pwm_start(p, _writeFreq, ulValue, _internalWriteResolution);
      } else
#endif /* HAL_TIM_MODULE_ENABLED && !HAL_TIM_MODULE_ONLY */
      {
        //DIGITAL PIN ONLY
        // Defaults to digital write
        pinMode(ulPin, OUTPUT);
        ulValue = mapResolution(ulValue, _writeResolution, 8);
        if (ulValue < 128) {
          digitalWrite(ulPin, LOW);
        } else {
          digitalWrite(ulPin, HIGH);
        }
      }
  }
}