https://devzone.nordicsemi.com/f/nordic-q-a/5264/heart-rate-demo-stuck-at-softdevice_handler_initHi we are developing a customized Bluetooth smart PCB with the nrf51822, I load the softdevice 110 v 7.1.0 no problem, but when I load the heart rate demo app it stuck in softdevice_handler_init() exactely in this line: err_code = sd_softdevice_enableen-USTelligent Community 13Fri, 23 Jan 2015 22:15:43 GMThttps://devzone.nordicsemi.com/thread/18422?ContentTypeID=1Fri, 23 Jan 2015 22:15:43 GMT137ad170-7792-4731-bb38-c0d22fbe4515:df6b4c24-66ed-4379-976a-827a5e497182Matt Barr<p>Yes, LFCLKSRC selection options are enumerated in components/softdevice/s110/headers/nrf_sdm.h in the 7.x.x SDKs.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/18423?ContentTypeID=1Fri, 23 Jan 2015 14:36:48 GMT137ad170-7792-4731-bb38-c0d22fbe4515:441bda73-b378-42c1-add8-7202a344b771Tarik<p>How can I do this, is it in this line : SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_XTAL_20_PPM, false);</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/18421?ContentTypeID=1Fri, 23 Jan 2015 14:31:54 GMT137ad170-7792-4731-bb38-c0d22fbe4515:25fcba79-8275-4282-b4cd-eba7de37fa96H&#229;kon Alseth<p>Do you have a 32 kHz external source on your board? If not, then try changing the SOFTDEVICE_INIT() to use the internal 32 kHz RC oscillator and see if that works.</p> <p>Cheers, Håkon</p><div style="clear:both;"></div>