https://devzone.nordicsemi.com/f/nordic-q-a/22623/change-clock-source-52832I config the inner clock source like this #define NRF_CLOCK_LFCLKSRC {.source = NRF_CLOCK_LF_SRC_RC, \ .rc_ctiv = 16, \ .rc_temp_ctiv = 2,\ .xtal_accuracy = NRF_CLOCK_LF_XTAL_ACCURACY_20_PPM} When using external clock source(32.768khz),en-USTelligent Community 13Fri, 09 Jun 2017 09:43:51 GMThttps://devzone.nordicsemi.com/thread/88997?ContentTypeID=1Fri, 09 Jun 2017 09:43:51 GMT137ad170-7792-4731-bb38-c0d22fbe4515:301dee47-7b1c-4e12-8384-03dd5f61d6a5bjorn-spockeli<p>Ok, so if you change the clock source to the internal RC in the bootloader, like you did with the application, then the bootloader and application runs fine?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/88996?ContentTypeID=1Fri, 09 Jun 2017 09:39:02 GMT137ad170-7792-4731-bb38-c0d22fbe4515:05c7f416-722f-4da2-83a0-2a688d6c274drc766437<p>I know why, bcs bootloader config external clock,so if I take away the crystal, the pargram stuck bootloader....</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/88995?ContentTypeID=1Thu, 08 Jun 2017 08:43:23 GMT137ad170-7792-4731-bb38-c0d22fbe4515:c237a876-1b5c-4892-80d4-2410130b1b3cbjorn-spockeli<p>Could you debug the application and check that you reach the <code>SOFTDEVICE_HANDLER_INIT(&amp;clock_lf_cfg, NULL);</code> in ble_stack_init(). If you are able to reach a breakpoint after this macro call in ble_stack_init() ,then you need to check the error codes of the other functions in ble_stack_init(). Otherwise, step into the <code>SOFTDEVICE_HANDLER_INIT</code> macro and check the error code returned by <code>softdevice_handler_init()</code>.</p><div style="clear:both;"></div>