Nordic Dev Kit - how to detect if something is connected to DEBUG_OUT header?

[mikemike651]

Hi there,

We have a custom board that runs on a nRF52833 chip.

In order to flash firmware to that board, I use the Nordic DK (PCA10056), and connect my custom board to the DK's "DEBUG_OUT" port (J-link ribbon cable). I use nrfjprog to flash the custom board. This works great.

Sometimes my custom board can be flaky (not a problem related to Nordic), and in that case, when I use nrfjprog, it actually flashes the DK instead of my custom board. If this happens I just fix the flaky connector on my custom board, and try again and it works.

My question is, is there a way that I can see if the DK recognizes that something is plugged in correctly to the "DEBUG_OUT" port?

Alternatively, is there a way to specify with nrfjprog which target to flash? Can we tell it to flash only the target connected to "DEBUG_OUT", and not the DK itself?

Thank you!

[mikemike651]

Update: Spoke to a Nordic rep, and he suggested that we can use the following command to see what is attached to the debugger:

nrfjprog --deviceversion

This has been working well for me. If there is no device attached to the DEBUG_OUT port, it will show the dev kit's processor (for example, on the PCA10056 DK, it will show nRF52840). If a device is attached correctly to the DEBUG_OUT port, it will show the device's information (i.e. 52833 in my case). If access port protection is enabled, it will show "unknown", which is still an indicator that something is attached to DEBUG_OUT.

Thanks again for you help.