https://devzone.nordicsemi.com/f/nordic-q-a/46243/nrf52840-can-not-scan-any-ble-device-or-being-scanned-by-nrf-connect-on-my-customer-board-with-example-ble_app_att_mtu_throughputWith my custom board I can program it, debug it and it output log ok, but just can not be scanned or scanning any other ble devices. besides: the code works well in other demo board. the output log as fallows: [00:00:00.000,000] &lt;debug&gt; ble_scanen-USTelligent Community 13Tue, 16 Apr 2019 21:42:12 GMThttps://devzone.nordicsemi.com/thread/182474?ContentTypeID=1Tue, 16 Apr 2019 21:42:12 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3ced348a-c1bd-4f4d-a575-5334f7fdcb23paul<p>Glad to hear it is now working....</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/182282?ContentTypeID=1Tue, 16 Apr 2019 08:13:45 GMT137ad170-7792-4731-bb38-c0d22fbe4515:188e5450-48c3-439d-85c3-06c22c38b04azxd<p>Hi paul,</p> <p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Thanks for your fast answer.</p> <p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;I&#39;m sorry for forgetting to tell that my customer board has 32KHz crystal; and finally, after I change the 32MHz crystal from demo board to my board, it work ok , but I don&#39;t why that happen, the 32MHz crystal use load capacitor with value of 12pF as the same with demo board.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/182224?ContentTypeID=1Tue, 16 Apr 2019 04:54:46 GMT137ad170-7792-4731-bb38-c0d22fbe4515:580f19e7-f827-4154-bc85-62adb745e618paul<p>Hi Zxd,</p> <p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; one thing that always got me moving from the dk to my custom board was the clock source. Check sdk_config.h for&nbsp;NRF_SDH_CLOCK_LF_SRC. The DK board has a crystal so the default for config is to use the crystal. The Synth option combines the hf clock with the lf clock to fudge it. However it has high power drain. The RC one is the one to use if you don&#39;t have a crystal installed.</p> <p>hope this helps</p> <p>Paul</p><div style="clear:both;"></div>