Set WKUP pin to no push/pull after Standby STM32

[Robert Beckwith]

Posted on June 25, 2018 at 17:14

When I send the device into standby it appears that the WKUP pin is held low. For my application this causes an issue with the Comparator that is in the circuit before the pin. Is there a way to configure the WKUP pin to be no push/pull when it is sent into Standby mode?

I am using an STM32F437IIH6 chip on a custom board.

#wkup-pin #standby

[Ricardo Hassan]

Posted on July 02, 2018 at 18:53

Hi,

    If I understand correctly, you cannot configure a pin as a GPIO and a WKUP at the same time;  it must be one or the other.  If you had the pin configured as a GPIO, (assuming you are using HAL, otherwise do the equivalent action) then I would call HAL_GPIO_DeInit() on it, then configure the pin as WKUP using HAL_PWR_EnableWakeUpPin(PWR_WAKEUP_PINX_YYY) where X is the wakeup pin number and YYY is LOW or HIGH.  I believe the pin will float after that (from the MCU perspective), so whatever is controlling the other side should make sure the pin is in the right state.

Ricardo