RE: nrf52840 DK for nrf52811 development

nordicDK — Tue, 08 Oct 2024 00:07:09 GMT

Thanks for your wonderful advice!
Currently I am designing PCB using nrf52811 soc, I hope it work well.

RE: nrf52840 DK for nrf52811 development

Edvin — Mon, 07 Oct 2024 13:33:41 GMT

Hello,

The nRF52840 DK has two methods of programming external targets. One is the 10 pin DEBUG OUT port (P19) in the upper left corner. This is useful if your custom board has a 10 pin connector, which it sounds like your custom board doesn't have. The other way is to use P20, which is the long strip of GPIOs:

which does more or less the same thing.

So the way that both of these work is that when you connect your debugger on the DK to your computer, it will check if an external device is connected to either P19 or P20. If it detects anything, it will use that port instead of programming the nRF52840 on the DK. This goes for both debugging and programming. So in your case, it sounds like you should use P20. Depending on what version of the DK you have (it should say on the large white sticker, in addition to the serial number of the debugger), the name of the pins on P20 may be a little different. The thing is that you don't power the custom board via P20.

On the newer versions of the DK, this is described here:

https://docs.nordicsemi.com/bundle/ug_nrf52840_dk/page/UG/dk/hw_debug_out.html

But the same documentation for the nRF5340DK has an image, that is handy as well:

https://docs.nordicsemi.com/bundle/ug_nrf5340_dk/page/UG/dk/ext_programming_support_P20.html

The debug out part is the same on both the nRF52840DK and the nRF5340DK.

So basically, you need to connect:

DK -> Custom board

SWDIO -> SWDIO

SWDCLK -> SWDCLK

"GND Detect" (may not be named on the PCB, but same position) -> GND

SWD_Sel / VTG -> VDD

Note that SWD_Sel and GND detect does not power the external board, so you need to either power it externally (if so, make sure they have common ground, by shorting GND on DK to GND on custom board), or you can power it from VDD and GND on your DK (outside P20).

Let me know if it doesn't work.

Best regards,

Edvin