Issue in STANDBY Mode in stm32f746g discovery board.

[SGupt.7]

Hi everyone,

I am trying to implement the STANDBY mode in stm32f746g board using the system wakeup pin PI11 (user push button).

The issue is that once I press the button, the controller automatically wakes up from the STANDBY mode.

I have attached my code below for reference.

Also, if I want to use PA0 pin as the syswkup pin with an external button press to detect the falling edge, should I pass PWR_WAKEUP_PIN1_LOW in the function argument?

Any leads to the above problem would really help.

Thanks and Regards.

int main(void)
{
  /* 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 */
 
  if(__HAL_PWR_GET_FLAG(PWR_FLAG_SB) != RESET) {
	  __HAL_PWR_CLEAR_FLAG(PWR_FLAG_SB);
 
	  char *tx_buf = "MCU wakes from STANDBY mode!\n\r";
	  HAL_UART_Transmit(&huart1, (uint8_t *)tx_buf, strlen(tx_buf), HAL_MAX_DELAY);
 
	  //HAL_PWR_DisableWakeUpPin(PWR_WAKEUP_PIN6);
  }
 
  __HAL_PWR_CLEAR_FLAG(PWR_FLAG_WU);
 
  HAL_PWR_EnableWakeUpPin(PWR_WAKEUP_PIN6);
 
  char *str2 = "STANDBY mode ON!\n\r";
  HAL_UART_Transmit(&huart1, (uint8_t *)str2, strlen(str2), HAL_MAX_DELAY);
 
  HAL_PWR_EnterSTANDBYMode();
 
  /* USER CODE END 2 */
 
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */
 
    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

[Amel NASRI]

Hi @SGupt.7​ ,

Sorry, but I don't understand what is wrong with this behavior:

I am trying to implement the STANDBY mode in stm32f746g board using the system wakeup pin PI11 (user push button).

The issue is that once I press the button, the controller automatically wakes up from the STANDBY mode.

-Amel

[SGupt.7]

Hello,

Thanks a lot for your reply.

So just to make my problem more clear, whenever I press the user push button (PI11) for the 1st time, the MCU wakes up from the standby mode but in the next step it does not stay in standby mode and wakes up automatically even if I do not press the button again.

My requirement is that once I press the user push button PI11, the MCU should wake up from standby mode and then immediately go back in standby mode and stay in that low-power mode until I press the button again.

Perhaps this will make my doubt clearer to understand.

Thanks and Regard.