uint8_t flag = 0;
  uint8_t frequency = 0;
  /* USER CODE END 2 */

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

  /* USER CODE END WHILE */

  /* USER CODE BEGIN 3 */
      if(flag == 0)
      {
          frequency = 500;
          HAL_GPIO_WritePin(GPIOA, GPIO_PIN_5,GPIO_PIN_SET);
          HAL_Delay(frequency);
          HAL_GPIO_WritePin(GPIOA, GPIO_PIN_5,GPIO_PIN_RESET);
          HAL_Delay(frequency);
      }
      else if(flag == 1)
      {
          frequency = 250;
          HAL_GPIO_WritePin(GPIOA, GPIO_PIN_5,GPIO_PIN_SET);
          HAL_Delay(frequency);
          HAL_GPIO_WritePin(GPIOA, GPIO_PIN_5,GPIO_PIN_RESET);
          HAL_Delay(frequency);
      }
      else
      {
          frequency = 125;
          HAL_GPIO_WritePin(GPIOA, GPIO_PIN_5,GPIO_PIN_SET);
          HAL_Delay(frequency);
          HAL_GPIO_WritePin(GPIOA, GPIO_PIN_5,GPIO_PIN_RESET);
          HAL_Delay(frequency);
      }

/////////////////////////////////////////////////////////////////////

extern uint8_t flag;
/* USER CODE END 0 */

/* External variables --------------------------------------------------------*/

/******************************************************************************/
/*            Cortex-M3 Processor Interruption and Exception Handlers         */
/******************************************************************************/

/**
* @brief This function handles Non maskable interrupt.
*/
void NMI_Handler(void)
{
  /* USER CODE BEGIN NonMaskableInt_IRQn 0 */

  /* USER CODE END NonMaskableInt_IRQn 0 */
  /* USER CODE BEGIN NonMaskableInt_IRQn 1 */

  /* USER CODE END NonMaskableInt_IRQn 1 */
}

/**
* @brief This function handles Hard fault interrupt.
*/
void HardFault_Handler(void)
{
  /* USER CODE BEGIN HardFault_IRQn 0 */

  /* USER CODE END HardFault_IRQn 0 */
  while (1)
  {
    /* USER CODE BEGIN W1_HardFault_IRQn 0 */
    /* USER CODE END W1_HardFault_IRQn 0 */
  }
  /* USER CODE BEGIN HardFault_IRQn 1 */

  /* USER CODE END HardFault_IRQn 1 */
}

/**
* @brief This function handles Memory management fault.
*/
void MemManage_Handler(void)
{
  /* USER CODE BEGIN MemoryManagement_IRQn 0 */

  /* USER CODE END MemoryManagement_IRQn 0 */
  while (1)
  {
    /* USER CODE BEGIN W1_MemoryManagement_IRQn 0 */
    /* USER CODE END W1_MemoryManagement_IRQn 0 */
  }
  /* USER CODE BEGIN MemoryManagement_IRQn 1 */

  /* USER CODE END MemoryManagement_IRQn 1 */
}

/**
* @brief This function handles Prefetch fault, memory access fault.
*/
void BusFault_Handler(void)
{
  /* USER CODE BEGIN BusFault_IRQn 0 */

  /* USER CODE END BusFault_IRQn 0 */
  while (1)
  {
    /* USER CODE BEGIN W1_BusFault_IRQn 0 */
    /* USER CODE END W1_BusFault_IRQn 0 */
  }
  /* USER CODE BEGIN BusFault_IRQn 1 */

  /* USER CODE END BusFault_IRQn 1 */
}

/**
* @brief This function handles Undefined instruction or illegal state.
*/
void UsageFault_Handler(void)
{
  /* USER CODE BEGIN UsageFault_IRQn 0 */

  /* USER CODE END UsageFault_IRQn 0 */
  while (1)
  {
    /* USER CODE BEGIN W1_UsageFault_IRQn 0 */
    /* USER CODE END W1_UsageFault_IRQn 0 */
  }
  /* USER CODE BEGIN UsageFault_IRQn 1 */

  /* USER CODE END UsageFault_IRQn 1 */
}

/**
* @brief This function handles System service call via SWI instruction.
*/
void SVC_Handler(void)
{
  /* USER CODE BEGIN SVCall_IRQn 0 */

  /* USER CODE END SVCall_IRQn 0 */
  /* USER CODE BEGIN SVCall_IRQn 1 */

  /* USER CODE END SVCall_IRQn 1 */
}

/**
* @brief This function handles Debug monitor.
*/
void DebugMon_Handler(void)
{
  /* USER CODE BEGIN DebugMonitor_IRQn 0 */

  /* USER CODE END DebugMonitor_IRQn 0 */
  /* USER CODE BEGIN DebugMonitor_IRQn 1 */

  /* USER CODE END DebugMonitor_IRQn 1 */
}

/**
* @brief This function handles Pendable request for system service.
*/
void PendSV_Handler(void)
{
  /* USER CODE BEGIN PendSV_IRQn 0 */

  /* USER CODE END PendSV_IRQn 0 */
  /* USER CODE BEGIN PendSV_IRQn 1 */

  /* USER CODE END PendSV_IRQn 1 */
}

/**
* @brief This function handles System tick timer.
*/
void SysTick_Handler(void)
{
  /* USER CODE BEGIN SysTick_IRQn 0 */

  /* USER CODE END SysTick_IRQn 0 */
  HAL_IncTick();
  HAL_SYSTICK_IRQHandler();
  /* USER CODE BEGIN SysTick_IRQn 1 */
  if(!HAL_GPIO_ReadPin(GPIOC,GPIO_PIN_13))
  {
      if(flag == 2)
      {
          flag = 0;
      }
      else {
          flag++;
      }
  }
  /* USER CODE END SysTick_IRQn 1 */
}