Button Causing CPU freeze/SystemOff

[Dave_couling]

I have this odd issue which creeps up in field testing. Upon a button push the board goes immediately to System Off. 99.99% of the time Button pushes are handled normally, but in these rare cases while connected to a phone, the device will go straight to System Off upon a button push. Using SDK 6.1, S110 7.1

I was worried this could be happening because of one of the following reasons:

• Stack, app_timer and app_button all use the Scheduler. Perhaps this is a corner case that occurs when the Scheduler Queue is full?
• Perhaps the 32.768kHz crystal has drifted causing an assert according to DRGN-5153
• A fault in the GPIOTE within the app_button is hardfaulting?
• Noticed that in my on_sys_evt(uint32_t sys_evt) there is a system_off_mode_enter(); call on an NRF_EVT_FLASH_OPERATION_SUCCESS or NRF_EVT_FLASH_OPERATION_ERROR. Though it is unlikely to get here as I don't use pstorage anywhere in my application.

These are the only ways I can see this Button Freeze issue is occuring. I just thought I'd post this in case anyone else had seen this issue before. I read a similar post, which found a loop was blocking the Stack. I've verified none of my IRQ or scheduler handlers have any blocking.

Thanks guys,

DC

[Chris]

@Dave_coupling

Were you able to fix this issue?

I am having the same problem with my timers suddenly executing instantly (devzone.nordicsemi.com/.../).

I added the same rtc1_stop()/rtc_start() code into my button handler and can reliably re-create the problem too.