nrf52833 cannot use external 32M xtal. even uart with 9600 baudrate would fail to give right data.

My own 52833 board use QFN40 package.  DK use aQFN73 package.

I try the same code. and find DK can enable exernal xtal. while my own board cannot enable external xtal.

I mean the following code would not run out of the while loop.
NRF_CLOCK->TASKS_HFCLKSTART=1;
    while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0);   // cannot run out of this.

the wave picture from the cap (xc1 xc2) is like this.

both board would not enable external xtal.

what requirement is need to start external xtal?  I am stuck in this issue.

thanks.

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  • Hi,

    For the DEC3, you have used 1uF(100nF) but in the reference, it's 100pF. 

    Also, the ANT connection too, please make sure they are similar to the reference design, with the matching circuit.

    Regards,

    Priyanka

  • thanks a lot. 
    I will try it.
    would you please tell me what sub module would this DEC3 affect?
    and what for DEC5.  

  • Hi,

    From the reference you can see that the 820pF is only required for some chip revisions:

    -Priyanka