https://devzone.nordicsemi.com/f/nordic-q-a/100444/nrf52-dk-to-program-external-custom-prototype-boardHi, I&#39;m trying to program my custom board by connecting the nRF52-DK board to my custom board as indicated in the post below: My board is based around the FSC-BT630 module, which contains an nRF52832 chip. The only difference in the connectionsen-USTelligent Community 13Mon, 05 Jun 2023 14:14:54 GMThttps://devzone.nordicsemi.com/thread/429349?ContentTypeID=1Mon, 05 Jun 2023 14:14:54 GMT137ad170-7792-4731-bb38-c0d22fbe4515:43052587-e8d5-41ae-a5a4-f210dea68069Simonr<p>Hi</p> <p>GND_DETET is an input pin to the debugger to chek for the presence of an external device. So if the GND_DETECT is pulled low which I guess it is if you left it unconnected, the debugger won&#39;t find an external device connected. Can you also confirm that the custom board is connected from VDD to VDD&nbsp;<strong>and&nbsp;</strong>VTG on the DK?</p> <p><img alt=" " src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1595314095820v1.png" /></p> <p>Best regards,<br />Simon</p><div style="clear:both;"></div>