BSP header files and board selection

[Jean]

Hi.

I am on nRF52 DK (PCA10040 v0.9.0, s132 SD), SDK 0.9.2 and Linux (Ubuntu).

I am currently working on the SDK's example ble_app_uart.

I am only using gcc, and with the Makefile provided in the SDK, I'm able to run make, get the hex binary file and flash it to the nRF52 board. It works well.

My question : in the /examples/bsp folder, there are many header files : eg bsp.h, boards.h and also many board-specific files eg pca10040.h. boards.h is where the codes seems to select the right board-specific configuration (eg #elif defined(BOARD_PCA10040) / #include "pca10040.h"...). However I cannot find out where in the code the board.h header file is included, that is I do not understand where the code does specify which board is used (and eventually triggers boards.h to select the right pca10040.h header file).

The only place I can find a mention of the board model is in the Makefile (eg CFLAGS += -DBOARD_PCA10040) but I do not understand if / how this is ultimately passed to boards.h and select the associated pca10040.h file.

[Wojtek]

There is a line in boards.h:

#elif defined(BOARD_PCA10040)
#include "pca10040.h"

So, when you have BOARD_PCA10040 defines (which you have, because of CFLAGS), line "#include "pca10040.h" is used.

[Jean]

Thanks Wojtek. I have seen this line, but my question was more : where is boards.h being called (rather where is it included) in the overall C code? I cannot find it (apologies if it is obvious).

[Wojtek]

In ble_app_hrs example it is included in main.c file. I think in the rest of examples it is similar. It is not called anywhere. Defines from it are used in various places...

[Jean]

I agree that it seems like a natural place to be, but I cannot find any reference to boards.h in my nrf52_sdk_092/examples/ble_peripheral/ble_app_uart/main.c and that's my issue. Should I look somewhere else?

[Wojtek]

Ok, in that example boards.h is included by bsp.h. Boards.h includes pca10036.h, and it has definitions like buttons etc.

[Jean]

Thank you, it's there. For most example #include "board.h" is included in main.c but for ble_app_uart it isn't and bsp.h acts as a fallback it seems.