How to know MCU wake up reason ?

[enkavak]

Hello,

        I am using sd_power_system_off(); sfunction to put the MCU in sleep mode. I have to wake up events. One is NFC and the other is GPIO. Both wake up functions works well but I need to know that which one occurs When the MCU wakes up from sleep.

       How can I know the reason of the wake up ?

Best Regards

[enkavak]

I found a topic Which explains the reset reason by using the code below. However, I get 0x00000001 every time MCU wakes up. GPIO or NCF is does not matter. Whatever the reason is I get the same output.

reset_reason = NRF_POWER->RESETREAS;
NRF_LOG_PRINTF("reset_reason: 0x%08x.\n",reset_reason );

[haakonsh]

Hey enkavak,

Sorry for the late reply. Can you reproduce this issue on the nRF52DK? 

Cheers,

Håkon.