https://devzone.nordicsemi.com/f/nordic-q-a/19929/nrf52-moving-from-pca10040-to-my-hardwareHi ! I just got my new boards with the NRF52 CPU. When i burn the firmware that worked on the PCA10040 evk it works but on my hardware it resets immidiatly. On my hardware there are no Crystals/XTAL etc&#39;...I only use the internal RC for theen-USTelligent Community 13Wed, 22 Feb 2017 14:58:20 GMThttps://devzone.nordicsemi.com/thread/77559?ContentTypeID=1Wed, 22 Feb 2017 14:58:20 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8da6a4cf-c91d-4d45-94fa-32add68a4178Hung Bui<p>Hi Yuval,</p> <p>When you mentioned you don&#39;t have crystal/XTAL, you meant you don&#39;t even have the 32MHz crystal or it&#39;s the 32kHz crystal that you don&#39;t have ?</p> <p>Radio activity requires the 32MHz crystal, you can&#39;t run on the HFCLK RC.</p> <p>If it&#39;s only the 32kHz crystal you don&#39;t have, you only need to modify the code to use 32kHz RC. Modify NRF_CLOCK_LFCLKSRC to use .source = NRF_CLOCK_LF_SRC_RC</p><div style="clear:both;"></div>