https://devzone.nordicsemi.com/f/nordic-q-a/66043/what-is-the-difference-between-dk-board-and-j-link-when-using-external-debuggerHello! I&#39;ve only used the DK board so far, so I&#39;ve rarely used an external debugger. I&#39;m going to use a custom board later, so I&#39;d like to learn more about how to use an external debugger. To use an external debugger, can use DK board&#39;s on-board debuggeren-USTelligent Community 13Fri, 18 Sep 2020 07:36:05 GMThttps://devzone.nordicsemi.com/thread/270233?ContentTypeID=1Fri, 18 Sep 2020 07:36:05 GMT137ad170-7792-4731-bb38-c0d22fbe4515:382cb87b-9215-4b53-be90-6aa0f8c718cbAmanda Hsieh<p>Hi,&nbsp;</p> <p>&nbsp;<span>The&nbsp;</span><span>nRF52 DK</span><span>&nbsp;supports programming and debugging nRF51 and nRF52 devices mounted on external boards. To debug an external board with SEGGER J-Link OB IF, connect to the Debug out connector (</span><span>P19</span><span>) with a 10-pin cable. See&nbsp;<a title="Debug output" href="https://infocenter.nordicsemi.com/topic/ug_nrf52832_dk/UG/nrf52_DK/hw_debug_out.html?cp=4_2_4_5_9">Debug output</a>.</span></p> <p><span>If you don&#39;t have the J-link, you can use the&nbsp;on-board debugger on DK. They are the same.&nbsp;</span></p> <p><span>-Amanda H.</span></p><div style="clear:both;"></div>