STM32F7 PA0 as EXTI not working right -> BUG?

Dejan Nedeljkovic · ‎2019-09-18

Hi

I've configured a STM32F767II with CUBEMX and generated an Atollic TrueSTUDIO Project. PA0 is configured as external interuppt in IT_RISING Mode. The problem is that this EXTI triggers also at falling edges. Other EXTI pins were configured the same way and are working how excpected. Is there a bug in the STM32F7 HAL library for PA0?

Regards

Dejan

waclawek.jan · ‎2019-09-19

Are you sure the source of your pulses is clean, and there are no spurious multiple pulses at what you think is a single falling edge?

For example, mechanical switches tend to bounce and produce a series of pulses upon switching.

JW

Dejan Nedeljkovic · ‎2019-09-19

Hi Jan

The pulses should be good. I have connected the same button to another EXTI pin and it worked like excpected. It's not a mechanical issue.

First I had the PA0 pin set as SystemWakeUp in CUBEMX and then I changed it to EXTI. Maybe there are some confusions in the generated code.

I can't explain why HAL_GPIO_EXTI_Callback is been called on falling_edges of PA0 because it's configured to trigger only on rising edge.

Dejan