Programming custom NRF52832 board using NRF52-DK, updated supply PIN-Assignment

[nRF52_DK_usr]

Hi,

looking through many Posts regarding this topic, i recognized the wiring and labels of the nRF52 DK has changed.

GND is explicitly on the P20 Header anymore.

-nRF52 DK is supplied via USB

-custom board supplied by external power supply, 3.0V

My (nrf52832 custom board) has an explicit SWD Header, compatible to the nrf52 DK: VCC-1, RESET-2, SWD-3, SWDCLK-4, SWDIO-5, GND-6.

VS Code recognized the nRf52 DK, that's fine, but doesn't recognize or provide  my external board (for flashing) yet. Question:

What Voltage should be supplied on VTG (Pin 3) by the custom Board? I would assume 3.3V as is many posts noted, but don't want to assume.

The nRF52 DK User Guide doesn't contain that detail.

And where should the (SWD power supply) GND be connected to?

Like here:  External programming Using nRF52-DK 

Thanks for any hint.

[Kenneth]

Hello,

This answer should still be valid:  RE: nRF52 DK V3.0.0 Debug out for programming external board can't work 

You should measure the VDD voltage on the DK and compare with the VDD custom board and ensure the difference is less than 0.3V (or you can just take VDD from the DK to power your board to ensure they are equal). Also connect GND somewhere between the two boards.

Kenneth

[nRF52_DK_usr]

Hello,

thanks for the quick reply. So, following your explanation, the VDD is an Output, while all SWD1 are input Connectors?

Do i get that correct?

The "Main nRF52DK power domain" is/was confusing me to be an input.

[Kenneth]

Not sure I fully understand the question, but I guess you can say VDD and VDD_nRF on header P20 are outputs yes, since they can power circuitry externally. The SWDIO is bidirectional. The SWDCLK, SWO (optional), RESET (optional) are outputs. SELECT is an input pin (must be connected to VDD of the external board). GND is mandatory (but not on the P20 header, so must be connected somewhere else).

Kenneth