Configuring GPIOTE using hi-to-lo or lo-to-hi transition - what if the pin is already at the transition's end state?

[alnordic]

Hi everyone, I have a question about GPIOTE.

What happens if for example, GPIOTE is used to configure a pin to detect a low to high transition, but the pin is already high? Or vice versa, where a pin should detect a high to low transition, but the pin is already low?

Will an event be triggered? I have not been able to find documentation on this.

Thank you!

[bjorn-spockeli]

Hi alnordic, 

if the pin is already in its end-state when you configure the GPIOTE peripheral to generate a interrupt on a transition, then no event will be triggered until such a transition has occured, i.e. if the GPIOTE peripheral is configured to generate a event on a low to high transition and the pin is already high, then the pin must go low and high again for the event to trigger. 

Best regards

Bjørn

[alnordic]

Thank you Bjorn.

Do you see any issue with modifying nrfx_gpiote_in_event_enable() to manually set the event if the pin is already in its end-state?

I am using hi-accuracy TRUE in my application, so I will be working with the IN event.

[awneil]

alnordic said:

manually set the event

What is the event doing?

If it's just to be handled in software. why not  just call the event handler?

[alnordic]

Thank you for the suggestion awneil, I will use that in my application.