stm32F411外部中断和串口通信，按多了就亮起了故障指示灯，为什么？

我是用的是STM32F411nucleo板，使用了stm32cubemx，我想按一下蓝色的按钮就用串口的中断方式输出，但是试了几次有的时候好，但是按多了就亮起了故障指示灯，不知道错在哪里，请各位大虾帮忙看一下，不胜感激！

程序如下：
/**
  ******************************************************************************
  * File Name          : main.c
  * Date               : 11/03/2015 16:55:32
  * Description        : Main program body
  ******************************************************************************
  *
  * COPYRIGHT(c) 2015 STMicroelectronics
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *   1. Redistributions of source code must retain the above copyright notice,
  *      this list of conditions and the following disclaimer.
  *   2. Redistributions in binary form must reproduce the above copyright notice,
  *      this list of conditions and the following disclaimer in the documentation
  *      and/or other materials provided with the distribution.
  *   3. Neither the name of STMicroelectronics nor the names of its contributors
  *      may be used to endorse or promote products derived from this software
  *      without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************
  */
/* Includes ------------------------------------------------------------------*/
#include "stm32f4xx_hal.h"
#include "usart.h"
#include "gpio.h"
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
#define RXBUFFERSIZE                      10
uint8_t aRxBuffer[RXBUFFERSIZE];
FlagStatus myflage;
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
int main(void)
{
  /* USER CODE BEGIN 1 */
uint8_t aTxStartMessage[] = "nr ****UART-Hyperterminal communication based on IT ****nr Enter 10 characters using keyboard :nr";
uint8_t aTxEndMessage[] = "nr Example Finishednr";
#define TXSTARTMESSAGESIZE                   (sizeof(aTxStartMessage) - 1)
#define TXENDMESSAGESIZE                     (sizeof(aTxEndMessage) - 1)
myflage=SET;
  /* USER CODE END 1 */
  /* MCU Configuration----------------------------------------------------------*/
  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();
  /* Configure the system clock */
  SystemClock_Config();
  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_USART1_UART_Init();
  /* USER CODE BEGIN 2 */
  /* USER CODE END 2 */
  /* USER CODE BEGIN 3 */
  /* Infinite loop */
  while (1)
  {
    if(myflage==SET)
    {
      myflage=RESET;
    if(HAL_UART_Transmit_IT( huart1, (uint8_t*)aTxStartMessage, TXSTARTMESSAGESIZE)!= HAL_OK)
      {
        HAL_GPIO_WritePin(GPIOA, GPIO_PIN_5, GPIO_PIN_SET);
        while(1) //跳不出来就死在那里了
        {
        }   
       }
      while (HAL_UART_GetState( huart1) != HAL_UART_STATE_READY)
      {
        } //等待发送过程结束
    if(HAL_UART_Transmit_IT( huart1, (uint8_t*)aTxEndMessage, TXENDMESSAGESIZE)!= HAL_OK)
      {
        HAL_GPIO_WritePin(GPIOA, GPIO_PIN_5, GPIO_PIN_SET);//故障灯亮
        while(1) //跳不出来就死在那里了
        {
        }   
       }
    }
  }
  /* USER CODE END 3 */
}
/** System Clock Configuration
*/
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  __PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = 6;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLM = 16;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
  RCC_OscInitStruct.PLL.PLLQ = 4;
  HAL_RCC_OscConfig( RCC_OscInitStruct);
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
  HAL_RCC_ClockConfig( RCC_ClkInitStruct, FLASH_LATENCY_2);
}
/* USER CODE BEGIN 4 */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
   myflage=SET;
}
/* USER CODE END 4 */
#ifdef USE_FULL_ASSERT
/**
   * @brief Reports the name of the source file and the source line number
   * where the assert_param error has occurred.
   * @param file: pointer to the source file name
   * @param line: assert_param error line source number
   * @retval None
   */
void assert_failed(uint8_t* file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
    ex: printf("Wrong parameters value: file %s on line %drn", file, line) */
  /* USER CODE END 6 */
}
#endif
/**
  * @}
  */
/**
  * @}
*/
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/