STM32F405: exit low power STOP mode on external interrupt pin

[lan1]

Hello，

I want to use the PB6 pin as an external interrupt input. When the PB6 pin is triggered, the program enters the low-power stop mode from the normal operation mode. When it is triggered again, the program enters the normal operation mode from the low-power stop mode. According to the above, the test found that after the program enters the low-power mode, it cannot return to the normal operation mode again.

Does anyone have experience in this area and can provide me with a solution?

[TDK]

Don't enter low-power mode from within an interrupt. Set a flag and do it in the main thread.

Additionally, if this is a button, you will probably have to debounce it.

[QSHAO.1]

Some information about how to exist stop mode (refer to RM0090), hope it's helpful.

If WFI or Return from ISR was used for entry:
Any EXTI lines configured in Interrupt mode (the corresponding EXTI
Interrupt vector must be enabled in the NVIC). The interrupt source can
be external interrupts or peripherals with wake-up capability.

 
If WFE was used for entry and SEVONPEND = 0
Any EXTI lines configured in event mode.

If WFE was used for entry and SEVONPEND = 1:
– Any EXTI lines configured in Interrupt mode (even if the corresponding
EXTI Interrupt vector is disabled in the NVIC). The interrupt source can
be an external interrupt or a peripheral with wake-up capability. 

[lan1 · Accepted solution]

@QSHAO.1  @TDK   hello I configured PB6 as an external input interrupt. The configuration is as follows, and I am certain that this function is normal and effective.

EXTI_InitTypeDef EXTI_InitStructure;
  NVIC_InitTypeDef NVIC_InitStructure;


  RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);


  SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOB, EXTI_PinSource6);

  EXTI_InitStructure.EXTI_Line = EXTI_Line6;
  EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
  EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
  EXTI_InitStructure.EXTI_LineCmd = ENABLE;
  EXTI_Init(&EXTI_InitStructure);

  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);


  NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x03;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x03;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

 And I placed the low-power mode in the time slice polling. Meanwhile, the PB6 pin is self-resetting and will only be triggered once at a time.

 PWR_EnterSTOPMode(PWR_Regulator_LowPower, PWR_STOPEntry_WFI);
    SystemInit();

[TDK]

Show your full code.

[MM..1]

Seems your code is normal and effective, then why you ask? 

We ask where you start GPIO CLK, next why you call SystemInit after wake ? ETC.

[lan1]

@MM..1  According to the official data sheet, after exiting the stop mode, the system clock needs to be reset first.

Based on the current transformation, I was certain that entering the stop mode was effective, but when I wanted to exit the low-power mode again, the program did not run normally