NRF52840 does not restart after a reset

[bgarrood]

On my board using an NRF52840 the module does not automatically restart after a pin reset.

If I shutdown using sd_power_system_off() then the device automatically restarts.

After a pin reset I can only get the device to restart by physically attaching the programmer, a j-link lite (once physically connected it restarts without me having to do anything else)

Seems my problem is similar to this:

https://devzone.nordicsemi.com/f/nordic-q-a/14618/nrf52-does-not-start-without-debugger

However I am not clear on where to set linker flags.  I am using Segger Embeded Studio.

Any suggestions much appreciated!

[Susheel Nuguru]

Hi Barnaby,

Not sure which SDK version you are using but you need to explicitly set the pin number to which you need your reset behavior in this UICR register. Also make sure that you set the default pull configuration using the gpio config to set the pin pull correct at system start.

[bgarrood]

Thank you.  I'm using SDK 17.0.2

I found out the issue was due to a board layout problem, but actually your suggestions about pull-ups may enable me to work around.  So thank you!

[Susheel Nuguru]

You are welcome and thanks for writing the reason for the issue you are seeing. It makes this thread complete and useful to others. Please mark this thread as verified if you consider this issue resolved.