Can Internal RC be used for BLE comms?

[nordicdev]

MS76SF2_SCH_V12.pdfHi, I am using SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_SYNTH_250_PPM, NULL); for ble_Stack_init() because the off the shelf board (not from Nordic) goes into a never ending loop when SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_XTAL_20_PPM, NULL) is used. The external crystal does produce clock signals, but I think the loading capacitors are not right. Anyway, if I use NRF_CLOCK_LFCLKSRC_SYNTH_250_PPM, will this RC clock be accurate enough to keep the BLE connection (I am basically using ble_app_uart as base) going? Another question is, will the EMC testing pass with NRF_CLOCK_LFCLKSRC_SYNTH_250_PPM as clock source? Thanks.

[RK]

You can use the RC mode, the HFCLK synth one is not recommended.

You should also work out why the external crystal isn't working. Write a bit of code to start it by using the clock drivers and check the frequency.

[nordicdev]

Hi RK, Thanks for the response. The same code that was working on one of our custom made boards is not working on the off the shelf product from a 3rd party. So, I came to a conclusion that the loading capacitors are not right in the off the shelf product. Is there any example/code snippet where I could start the crystal using clock drivers and check the frequency? Thanks.