板上资源

LD1: PC7
LD2: PB7
LD3: PB14
Button: PC13

ST-LINK UART: lpuart1(PG7/PG8)

注意，L4R5_NUCLEO板子，时钟不能选HSE（不能work），要选择HSI即可

LED/串口Demo

int main(void)
{

  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_LPUART1_UART_Init();
  MX_USART3_UART_Init();
  MX_USB_OTG_FS_PCD_Init();
  /* USER CODE BEGIN 2 */

  char str[]="hello world!\r\n";
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
	  //HAL_StatusTypeDef HAL_UART_Transmit(UART_HandleTypeDef *huart, const uint8_t *pData, uint16_t Size, uint32_t Timeout)
	  HAL_UART_Transmit(&hlpuart1,
			  str,
			  strlen(str),
			  1000
			  );
	  HAL_UART_Transmit(&huart3,
			  str,
			  strlen(str),
			  1000
			  );

	  //void HAL_GPIO_TogglePin(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
	  HAL_GPIO_TogglePin(GPIOB, LD2_Pin|LD3_Pin);
	  HAL_GPIO_TogglePin(GPIOC,LD1_Pin);
	  HAL_Delay(1000);

  }
  /* USER CODE END 3 */
}