Running basic tutorial on custom breakout board

[Justin]

Hello,

What changes need to be made to the following tutorial to enable basic advertising with the Rigado BMD-300 on a custom board breakout board?

devzone.nordicsemi.com/.../

I've ripped out everything to do with the LEDs and buttons, but I'm still not seeing any advertising data with my custom board.

CONTEXT:

• Verified the code works on the Rigado BMD-300 Series Evaluation Kit.
• Verified a basic main.c can run on my custom board with a BMD-300.
• I'm initializing the clocks with this: APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_OP_QUEUE_SIZE, false);
• I have also gone through the following blog post: rigado.zendesk.com/.../225674668-Example-files-will-not-run-on-my-hardware-but-do-on-the-Eval-board-

[AmbystomaLabs]

Well that kind of points to a hardware problem. The only difference between the 300 and 301 is an external vs. internal antenna.

The options I see are:

1. Something isn't soldered down correctly module to your board.
2. The BMD-300 module is bad
3. The BMD-300 module might have a pre-production nRF53832 which have some unique software needs.
4. Something is messed up with your RTC circuit on your breakout board.

I would start first by changing the init statement for the SD to run off the internal RC RTC. That should answer number 4.

[Justin]

Are there other examples that are easily portable that I can test? Basically, I want an example project that does not interact with its breakout board (completely self-contained) or one I can modify easily to make it so.

[AmbystomaLabs]

Here is a basic beacon app with with internal RC RTC turned on and no led activity. If this doesn't work your bmd-300 is just broken.

Unzip it and do an erase all from nrfgo studio. then install the sd132 file first then install the application hex. the board will reboot on it own after finishing the application install. The beacon will show up in any beacon app. It has the normal nordic uuid of 0112233...etc.

zip file link here

[Justin]

Thanks so much! That project works! Great, so this is looking like a software issue.

[AmbystomaLabs]

Well what you mean is you likely have a problem with your external crystal based RTC. The trick that makes the software work is to tell the nRF to use its internal RC based RTC. Depending on your timing requirements you may/may not need a crystal based RTC. When it uses the internal RC the nRF calibrates it periodically against the main 32MHz clock. Since the ppm accuracy of the main clock is probably inferior to that of your external 32K clock the RC based RTC will never be as accurate. It may not matter for you though. We don't use an external RTC on our products.

Here is the code that makes the difference. It is in the board header file.

#define NRF_CLOCK_LFCLKSRC      {.source        = NRF_CLOCK_LF_SRC_RC,            \
                             .rc_ctiv       = 16,                                \
                             .rc_temp_ctiv  = 0}