Using MDBT42Q and BLE

[JimP]

Hello:

I'm relatively new and have been using 52832 DK for several months without any problems.  It is a great product.  As I gained experience, I've tried programming other boards (GT52832_A01) using a mini J-Link that I bought from Adafruit - again without problems. All of the example programs load and run on both DK and GT boards as expected.

I recently bought a few MDBT42Q modules from Mouser (they are made by Seeed Studios).  I believe this is the same module used by Adafruit on their Featherboard 52832, so I thought this would be a good product to expand my experience.  I was able to program the MDBT42Q boards using the J-Link, however, when I try to use anything with BLE the program loads but I'm not able to connect to the board via BLE.  I load the soft device loads and then the program the same way as with the DK and GT boards, except I'm not able to connect to the MDBT42Q board.  It is as if the board isn't advertising.

I did a search in the DevZone and found one post by Sudarshan J 10 months ago that looked similar to my problem but I'm not sure how to proceed and hope you might suggest some things to try.  

The datasheet for the MDBT42Q basically says that you don't need any external circuitry to make the module work, so it may not be a clock problem - but I'm not sure.  Since the module works fine (I can load simple blinky programs and program gpio, etc), I think I'm missing something simple.  

Any suggestions?

A related question - I tried to use debug to set breakpoints before and after the advertising function to try to see what was happening.  I tried to go stepwise through the program but execution just stops - so I must be missing something there as well.  There is a warning that there is a 32Kb limit on evaluation in debug - is that the problem?  Any suggestions?

Thank you for your help.

[awneil]

JimP said:

MDBT42Q modules from Mouser (they are made by Seeed Studios)

You mean these: https://www.mouser.co.uk/ProductDetail/Seeed-Studio/317030213?qs=sGAEpiMZZMs1xdPSgahjwiL2lJlP6L5V96Mk9IiRNC0%3d ?

JimP said:

The datasheet for the MDBT42Q basically says that you don't need any external circuitry to make the module work, so it may not be a clock problem - but I'm not sure

Probably means that you have to configure it to use the internal oscillator - have you done that?

JimP said:

I believe this is the same module used by Adafruit on their Featherboard 52832

Would be a good idea to get an Adafruit  Featherboard 52832 - then you'd at least have a know-good hardware  platform to start with ...

JimP said:

There is a warning that there is a 32Kb limit on evaluation in debug

Are you using Keil, then?

Segger Embedded Studio (SES) is free & unlimited for use with Nordic ARM-based SOCs ...

[JimP]

Yes.  I'm using the module you show in the link.  Yes - I'm using Keil as IDE - supplemented with nRFgo studio.

I haven't configured to use internal oscillator.  How would I do that?

The featherboard comes with Arduino IDE.  There must be a way to convert for Keil but I don't know how to do that.

Thank you for your help

[Einar Thorsrud]

Please keep a civil tone. awneil's questions and suggestions make full sense.

And to sum up: The only relevant difference between the 52832 DK and the MDBT42Q module is that the DK has a 32 kHz crystal and the module does not. So as long as you remember to configure the SoftDevice to use the internal 32 kHz RC instead of the non-existing 32 kHz crystal oscillator everything should work as on the DK.

[JimP]

here is what I've learned.

From the pack installer load the "experimental_ble_app_blinky_s132_pca10040" example.

connect the MDBT42Q and erase the chip with nRFgo Studio.

Load the Softdevice.

In the program comment out //SOFTDEVICE_HANDLER(NRF_CLOCK_LFCLKSCR_XTAL_20_PPM, false);

replace with :

SOFTDEVICE_HANDLER(NRF_CLOCK_LFCLKSCR_RC_250_PPM_250MS_CALIBRATION, false);

load the program.  You should be able to connect by running the nRF Blinky app on your phone.  The LED on/of will toggle pin 17 and if you ground pin 13 you should see the button pressed/released toggle on the phone.

There is still a problem with UART programs - they don't use SOFTDEVICE_HANDLER.  What is the difference between using SOFTDEVICE_HANDLER and the way connection is managed with UART program?

[etx]

He is rude and looking at his post history he has that tone with everyone. I'll just switch to another platform if that is how this community is run.

[etx]

I got mine going on the MDBT42Q, i think it was an issue with the default pca10040 board header. After switching to a custom board definition it's working. 

I'd love to try loading the same example you are to help but I cannot find that example. I'm using nRF5_SDK_15.2.0_9412b96.zip and building with armgcc for my application. Let me know.

[JimP]

That's great.  I'm using nRF5_SDK_15.0.0_a53641a.  But the example is from the pack installer.

Go to pack installer and under Nordic select nRF52832 on left side.  On right side click on Examples tab.

Go down to "Experimental_ble_app_blinky_s132_pca10040" and copy to a folder.  Keil will open with the example loaded and you should be able to make the clock change (SOFTDEVICE_HANDLER) without problem.  You will need to load the nRF_blinky app on your phone to test.

Tell me how to change to a custom board so I can try that.  What board should I put into the header?

The thing I find interesting is that the example using the SOFTDEVICE_HANDLER works when you change the clock, but the UART example doesn't after making the same changes to the config file.  I'm sure it must be something simple but haven't figured it out yet.

Thank you for continuing to work on this - much appreciated.

[awneil]

JimP said:

Tell me how to change to a custom board

The "official" way is to add to boards.h:

:
:
#elif defined (BOARD_D52DK1)
  #include "d52_starterkit.h"
#elif defined (BOARD_ARDUINO_PRIMO)
  #include "arduino_primo.h"
#elif defined (CUSTOM_BOARD_INC)
  #include STRINGIFY(CUSTOM_BOARD_INC.h)
#elif defined(BOARD_TOM)
  #include "tom.h"
#elif defined(BOARD_DICK)
  #include "dick.h"
#elif defined(BOARD_HARRY)
  #include "harry.h"
#elif defined(BOARD_CUSTOM)
  #include "custom_board.h"
#else
#error "Board is not defined"

Take, say, your DK board header and use that as the basis for creating your custom one.

infocenter.nordicsemi.com/index.jsp

devzone.nordicsemi.com/.../supporting-a-custom-board-with-nrf5-sdk-examples

Or, for a quick check, just hack the DK file!

JimP said:

the example using the SOFTDEVICE_HANDLER works when you change the clock, but the UART example doesn't

So step through the code in each case, and see where they diverge?

Because stepping & breakpoints are likely to crash the SoftDevice, you may need to look into Monitor Mode Debugging:

https://devzone.nordicsemi.com/b/blog/posts/monitor-mode-debugging---revolutionize-the-way-you-debug-ble-applications

https://github.com/NordicPlayground/j-link-monitoring-mode-debugging/#monitor-mode-debugging-in-keil-%C2%B5vision5-and-segger-embedded-studio

and/or instrument the code with RTT or whatever ...

[Einar Thorsrud]

The pack installer examples are very outdated and should not be used. They are not compatible with SDK 15. CMSIS Pack have not been used to distribute the SDK for a long time, as it was deprecated with the release of SDK 10 (see Deprecating support for CMSIS Pack in nRF5 SDK).

You will find an updated and compatible ble_app_blinky example in SDK 15 under <SDK>\examples\ble_peripheral\ble_app_blinky. In a nutshell: Unless you are working with legacy code which predates SDK 10 you should never use the pack installer to install or use any SDK component.

[JimP]

Thank you all for your patience and help.  I'll try your suggestions and let you know how it worked.