The nRF52 PDK supports programming and debugging external boards. To debug an external board, connect to the Debug out connector (P19) with a 10 pin cable.
Figure 1. Debug output connector
When the external board is powered, the interface MCU will detect the supply voltage of the
board and program/debug the target chip on the external board instead of the on-board nRF52832.
Important: The
voltage supported by external debugging/programming is 3.0 V.
You can also use P20
as a debug out connection to program shield mounted targets. For the Debug out header
(P19), the Interface MCU will detect the supply voltage on the mounted shield and
program/debug the shield target. If the Interface MCU detects target power on both P19 and P20, it will by default program/debug the target connected to P19.