GPIO INTERRUPT

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GPIO INTERRUPT

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sushma
Contributor III

Hello

I want to trigger an interrupt at both edges ( high-to-low and low-to-high), but my GPIO is pulled high externally (on hardware). So my IRQ gets triggered as soon as the system is powered (as it is pulled up externally, it sees low-to-high and fires IRQ)

I want to ignore the initial/first trigger (which is present in my hardware design and is not due to external system it is connected to). So what is the right procedure/steps to attach an IRQ in my case.

Steps followed so far :

Present Scenario : (a) Pin made to detect both edges

                               (b) Pin pulled high - externally

                               (c)IRQ triggered

Steps incorporated : (a)Cleared pending IRQ

                                 (b)Enabled IRQ

                                 (c) Attached handler

Kindly let me know the solution for the problem I'm facing at the earliest.

Thank you

Sushma Mantagani

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jorge_a_vazquez
NXP Employee
NXP Employee

Hi Sushma Mantagani

If I understood correctly, your MCU is already powered and after your pin is pulled up externally with other power supply, am I correct? You cannot avoid detecting only one interruption, but you could disable the interruption until you need it. For example, you could have disabled the pin interruption, pull high your pin and then enable the interruption in the pin.

Best regards

Jorge Alcala

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