MDBT-42V with nRF52DK

RE: MDBT-42V with nRF52DK

Edvin — Mon, 19 Mar 2018 12:00:25 GMT

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

RE: MDBT-42V with nRF52DK

Sudarshan J — Mon, 19 Mar 2018 06:31:42 GMT

Thanks for the response, Sir. We were successful in dumping the blinky example and other codes which did not use a softdevice, into our target board. We are currently having issues with BLE codes. Our schematics has the X2 (32Khz) crystal. We are able to communicate with the nRF Development board, but our target board isn't responding to BLE. What may be a possible solution to this?

RE: MDBT-42V with nRF52DK

Edvin — Thu, 15 Mar 2018 18:18:38 GMT

Hello,

I saw the documentation for the MDBT42V here. In section 8 you can see the pinout. In the upper right corner is the J-Link module, which has the same layout as the nRF5x DK. Make sure to use the "Debug Out"/P22 pins.

I attached the PCA10040 schematics, which you can also find here (nRF52-DK-HW near the bottom of the page)

devzone.nordicsemi.com/.../PCA10040_5F00_Schematic_5F00_And_5F00_PCB.pdf

I don't know if you have tried this, but if you have, and you don't get the examples to work, do you have an Low Frequency crystal on the PCB (The X2 in the schematics for the MTBT42V in section 8)? Or do you use the RC Oscillator? To check whether this is the problem, try one of the examples that does not use the softdevice, such as the SDK\examples\peripheral\blinky example.

Best regards,

Edvin