Programming an external board through SWD

[Jens Strümper]

Hi there, I'm trying to program an external nrf51 board (Xuntong 5518) through the nrf51-DK Debug out connector. So far I have no success and I'm wondering if I have the correct PIN's connected. I power the Xuntong with VDD and GND from connector P1 and connect SWDIO (PIN 4 connector P20) and SWDCLK (PIN 5 connector P20). I tried the P19 header with a olimex JTAG adapter as well . When I drag my hex file to the flash drive the internal nrf51 is flashed only. I don't exactly know how I would recognize the external board using JLINK as there seems to be no serial number or so. However when I use nrfGo Studio I see application and softdevice which I would not expect to see when I'm connected to the correct nrf.

Any help would be greatly appreciated!

Regards, Jens

[Susheel Nuguru]

From Section 5.10 in the nRF51-DK - User Guide:

The nRF51 DK board supports programming and debugging of external boards. To debug an external board, connect to the Debug out (P19) connector with a 10 pin cable.

When the external board is powered, the interface MCU will detect the supply voltage of the board and program/debug the target chip on external board instead of the on-board nRF51422.

[Susheel Nuguru]

I am not sure of drag and drop into the flash drive. I think that will work only for nRf51 chip or to those chips that Segger supports. If segger does not support your chip then You need to take control of the debug out port to tell it how to flash into the custom board.