https://devzone.nordicsemi.com/f/nordic-q-a/25375/definition-of-clock-parameters-in-sdk14-sdk_config-hI ran into the issue where the clock definitions were defined in both the &quot;board_pcaXXX.h&quot; file and the sdk_config.h. e.g. NRF_SDH_CLOCK_LF_XTAL_ACCURACY NRF_SDH_CLOCK_LF_SRC NRF_SDH_CLOCK_LF_RC_CTIV NRF_SDH_CLOCK_LF_RC_TEMP_CTIV I didn&#39;t realizeen-USTelligent Community 13Tue, 26 Sep 2017 12:47:29 GMThttps://devzone.nordicsemi.com/thread/100007?ContentTypeID=1Tue, 26 Sep 2017 12:47:29 GMT137ad170-7792-4731-bb38-c0d22fbe4515:7910783d-d6a9-46ee-95c4-4d5139553b2aSigurd<p>Hi,</p> <p>Even if the board itself have or don’t have an external LF crystal, you still have the option to configure the SoftDevice to use the internal LF-RC and how often the SoftDevice should calibrate the clock source. They are connected, since the board limits the available clock sources, but in the end you are not really configuring the board here, you are configuring the SoftDevice.</p> <p>And also generally you want to have a single place to configure your project (sdk_config.h).</p><div style="clear:both;"></div>