Cannot program board with NRF52840-dk using P19 connector.

[Vladislav Yegorov]

Hello,

I would like to use the P19 connector present on the NRF52840-dk (3.0.2) for programming/debugging my custom board, but unfortunately it doesn't seem to work.

For convenience sake I bridged the SB47 solder bridge, which should supply my board with power.  I verified that the power works.

When I try to program it, the development board gets programmed instead!  At first I thought it might be an issue with my custom board, luckily I have also the dongle board and soldered a 10-pin connector to the footprint at the bottom.  I can observe the exact same behavior on the dongle.

In the documentation there is explained that is should not be possible to program the onboard chip while SB47 is bridged, but maybe revision 3.0.2 has different behavior. I could not find any documentation for the newer devboards.

Is there something I may have missed?

Thank you and kind regards.

[Kenneth]

Hello,

The user guide should describe how you can connect either P19 or P20 for programming external board, see my comment here:
RE: nRF52 DK V3.0.0 Debug out for programming external board 

I did debug a difference between v2.2.0 and v3.0.0 in the above case, and you can find the detailed findings here:
RE: nRF52 DK V3.0.0 Debug out for programming external board can't work 

I suggest you check those out, hopefully it should make it work (though I think the specific case I linked too have a damaged board).

Kenneth

[Vladislav Yegorov]

Thank you for your fast reply, I was able to debug the issue.  The problem was that GND_DETECT was not connected properly.  Now my board is being detected just fine.

Thanks a lot for your assistance.