stm32 UART 통신으로 led 제어하고 Buzzer 여러 소리 내기

#
코드

if(rxflag == 1)
{
  rxflag = 0;
  uint8_t rxdata = LL_USART_ReceiveData8(USART1);
  LL_USART_TransmitData8(USART1, rxdata);
  if(rxdata == 'h' || rxdata == 'H')
  {
  HAL_GPIO_WritePin(GPIOC, GPIO_PIN_0, GPIO_PIN_SET);
  HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_SET);
  }
  else if(rxdata == 'l' || rxdata == 'L')
  {
  HAL_GPIO_WritePin(GPIOC, GPIO_PIN_0, GPIO_PIN_RESET);
  HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_RESET);
  }
  else if(rxdata == '1')
  {
  HAL_TIM_PWM_Start(&htim3, TIM_CHANNEL_1);
  TIM3->PSC = 35294/261-1;
  HAL_Delay(200);
  HAL_TIM_PWM_Stop(&htim3, TIM_CHANNEL_1);
  }
       .....
}

#
HAL_TIM_PWM_Start(&htim3, TIM_CHANNEL_1); @
TIM3->PSC = 35294/261-1;
HAL_Delay(200);
HAL_TIM_PWM_Stop(&htim3, TIM_CHANNEL_1); @

@ : 이것을 작성하지 않으면 소리가 끊기지 않는다.