nRF52 Softdevice Stuck without External Low Frequency Clock Source

Question

Hi, 
 I have developed custom nrf52832 board without external low frequency clock source. 
 So with that configuration I got problem when try to connect it through nRF MESH app. 
 As I found issue come with the soft device. So I add 32.768kHz crystal and two caps now module work fine. 
 But is there anyway to run device without external low frequency clock source ? 
 I'm using SDK 15.2, Mesh SDK 3.0, and softdevice S132 V6.1.0 
 Thank you

haakonsh · Accepted Answer

Yes, you can use the LF RC oscilator as the LF source, but you need to set the accuracy to 500ppm, otherwise, you will not be able to have BLE communication. You need to call sd_softdevice_enable with a correct nrf_clock_lf_cfg_t config. Set .accuracy to NRF_CLOCK_LF_ACCURACY_500_PPM , see Clock accuracy . 
 Set .source to NRF_CLOCK_LF_SRC_RC , see Possible LFCLK oscillator sources . 
 Set .rc_temp_ctiv to 0. 
 Set .rc_ctiv to 16.

nRF52 Softdevice Stuck without External Low Frequency Clock Source

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