MDBT-42V with nRF52DK

[Sudarshan J]

We are using an MDBT42V(29 pin) module which we discovered from the datasheet, comes with an nRF52832 controller. We are using a nRF52 DK to dump codes into this target board. But have so far been unsuccessful. Wanted to know if this is possible or if there's something else we should be doing. 

[Edvin]

Hello Sir,

It sounds like there is a problem with the external 32KHz crystal. 

Can you test the following code, and see if it hangs in one of the while-loops?

 

    NRF_CLOCK->TASKS_HFCLKSTART = 1;
    while(NRF_CLOCK->EVENTS_HFCLKSTARTED == 0);
    NRF_CLOCK->TASKS_LFCLKSTART = 1;
    while(NRF_CLOCK->EVENTS_LFCLKSTARTED == 0);

 

This way you can check if there is a problem with one of the crystals.

 

Referring to the spec of your module:

http://www.raytac.com/download/MDBT42/MDBT42V%20&%20MDBT42V-P-Version%20B.PDF 

in section 8:

What is your C_12 and C_13?

They should be:

C_L is the crystal capacitance, while C_pin = the capacitance of the pins on the nRF. They are 4pF.

As a reference, the development kit uses a LFXtal with C_L = 8pF. This gives:

so C_12 and C_13 is 12pF.

If you have a crystal with a different load than 8pF, you must adjust your C_12 and C_13 accordingly.

 

Best regards,

Edvin