2025-09-15 9:56 AM
Hi all,
I’m working on a project using an STM32F407 and running into issues with low-power modes. I can put the MCU into STOP mode successfully, but when I try to wake it up with an external interrupt (EXTI line on a GPIO pin), nothing happens. The device just stays stuck until I reset it manually.
Here’s what I’ve tried so far:
Configured the EXTI line with rising-edge trigger.
Verified the interrupt works fine when the MCU is running normally.
Enabled the corresponding NVIC interrupt before entering STOP mode.
Added __WFI() after setting STOP mode in the power control register.
Despite this, the MCU never wakes up when the pin is toggled. I must be missing something in the clock or power configuration, but I can’t figure it out.
Has anyone dealt with this before on STM32F4 (or similar STM32 family)? Any pointers on debugging wake-up sources in STOP mode would be a huge help.
Thanks!
2025-09-15 12:14 PM - edited 2025-09-15 12:14 PM
Perhaps follow a working example: