P0.11 on NRF5340 is not available as a GPIO due to net core hardcoded assignment, is editing the ncs code safe?

[JustinL]

Hi,

I need to use P0.11 on NRF5340 as a standard GPIO controlled by the application core. It has taken me a number of hours to realise why it isn't working as expected.

The net core reset code appears to hard code pin assignment for this to the net core for use by the uart. 

I can change the NCS code to alter this but since this is hardcoded it would seem likely it is hardcoded for a reason.

Can you confirm if changing the pin assignment will have unexpected side effects e.g. net core debugging not working on the DK, etc?

Obviously, I am not particularly keen on editing the NCS code base as this change is not checked into my revision control, unlike configuration options. Is there any chance this will become a configuration option in the future? If not then maybe I should create a new net core board configuration and check that into my revision control.

Thanks,

Justin

[Jared]

Hi,

I need to use P0.11 on NRF5340 as a standard GPIO controlled by the application core. It has taken me a number of hours to realise why it isn't working as expected.

The net core reset code appears to hard code pin assignment for this to the net core for use by the uart. 

Correct.

Can you confirm if changing the pin assignment will have unexpected side effects e.g. net core debugging not working on the DK, etc?

As of right now, I don't see any side effects except for missing logging info from the network core. But this might change in future releases.

Obviously, I am not particularly keen on editing the NCS code base as this change is not checked into my revision control, unlike configuration options. Is there any chance this will become a configuration option in the future? If not then maybe I should create a new net core board configuration and check that into my revision control.

I would expect this to be changed in the future, so that the pins are assigned via DTS or overlay accordingly to the comments in nrf5340_cpunet_reset.c

regards

Jared 

[JustinL]

Okay, thanks for the confirmation.