Trying to program an MDBT42Q nRF52832 based BLE module from an nRF52-DK as external target on connector P20. I used to do this with nRF51-DK and external nRF51 modules with success. Trying the same with nRF52-DK and MDBT42Q I'm not having any success. .hex is generated in MBED online IDE and runs fine on the nRF52-DK itself. Seemingly the external target is not detected and I'm ending up programming the nRF52-DK itself. Tried the following pin connections with both externally powered target and powering it from nRF52-DK.
nRF52-DK Custom / External Board
VDDnRF ---+-------------> VDD
|
VTG ------+
GND ------------+-------> GND
|
GND DETECT -----+
SWD IO -----------------> SWD IO
SWD CLK ----------------> SWD CLK
Also tried with some variation VDD instead of VDDnRF
VDD ------+-------------> VDD
|
VTG ------+
GND ------------+-------> GND
|
GND DETECT -----+
SWD IO -----------------> SWD IO
SWD CLK ----------------> SWD CLK
Also tried connecting GND DETECT to GND on the nRF52 itself
