main.c 可以添加一句打印提示

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 */

  if(IS_ENGINEERING_BOOT_MODE())
  {
    /* Configure the system clock */
    SystemClock_Config();
  }

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_UART4_Init();
  /* USER CODE BEGIN 2 */
printf("test for all...\n");
  /* USER CODE END 2 */

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

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

gpio.c 添加

/* USER CODE BEGIN 2 */
void HAL_GPIO_EXTI_Falling_Callback(uint16_t GPIO_Pin)
{
		switch (GPIO_Pin)
				{
				case GPIO_PIN_7:
					HAL_GPIO_TogglePin(GPIOF,GPIO_PIN_10);
				printf("led2 toggle...\n");
					break;
				case GPIO_PIN_8:
					HAL_GPIO_TogglePin(GPIOE,GPIO_PIN_8);
				printf("led3 toggle...\n");
					break;
				case GPIO_PIN_9:
					HAL_GPIO_TogglePin(GPIOE,GPIO_PIN_10);
				printf("led1 toggle...\n");
					break;
		}
	}
void HAL_GPIO_EXTI_Rising_Callback(uint16_t GPIO_Pin)
{
		switch (GPIO_Pin)
		{
			case GPIO_PIN_5:
				HAL_GPIO_TogglePin(GPIOE,GPIO_PIN_10);
				break;
			case GPIO_PIN_12:
				HAL_GPIO_TogglePin(GPIOF,GPIO_PIN_10);
				break;
			case GPIO_PIN_15:
				HAL_GPIO_TogglePin(GPIOE,GPIO_PIN_8);
				break;
	}
}
/* USER CODE END 2 */

usart.c 添加

/* USER CODE BEGIN 0 */
int fputc(int ch , FILE *STREAM)
{
	while(!(huart4.Instance->ISR &(0x1<<7)));
	huart4.Instance->TDR = ch;
	if(ch == '\n')
	{
		while(!(huart4.Instance->ISR &(0x1<<7)));
		huart4.Instance->TDR = '\r';
	}
	return ch;
}
/* USER CODE END 0 */

现象：