STM32H7 Series: Shutdown/Low Power Mode High-Level Question

[KMew]

Hello,

I am working with the STM32H7B3IIT6 MCU and it is controlling many features (CANbus, BLE, LCD Display, push buttons, etc.).

One feature we're going to have on our system, naturally, is a simple on/off button that powers the overall system on and off (peripherals off, display off, etc.). However, I am unfamiliar on how to do this in a way that does not limit the user's ability. In other words, I want them to be able to turn everything off with one button, then turn it on again with the same button in a toggling setup.

I'm unsure of the best approach for handling this so I have some high level questions.

1) Is there a way to enter a "low power" state for the MCU that is in standby mode?

2) IF yes to (1), will the peripherals automatically (CANbus, BLE, LCD, etc.) turn off when the MCU is in standby mode? Or do I have to de-initialize them as well?

3) What are the important things to consider when powering the MCU down?

4) Does entering standby require the use of specific IO pins?

I apologize if this is broad, but I need somewhere to start.

[KMew]

Hello Sarra,

Thank you for the confirmation. Yes, I have designated this pin solely for the system's on/off feature. If it is triggered, no other functionality will be utilized.

I have used the HAL EXTI features, so I do understand that portion. It's how to configure it to the WAKEUP pin that I'm confused about.

I've seen reference to HAL_PWR_EnableWakeUpPin(PWR_WAKEUP_PIN1) in code snippets, but how do I connect PB11 to PWR_WAKEUP_PIN1?

[Piranha]

> any GPIO pin configured as an external interrupt (EXTI) can be used as a wakeup (WKUP) pin from standby mode.

This is just wrong. The wake-up pins are special pins and are not related to EXTI at all. The particular pins can be found in datasheet or CubeMX (Power and Thermal => PWR). Typically there are 2-6 pins available and those are configured in PWR peripheral registers. PB11 is not a wake-up pin.