Adapting the blinky example from the nRF52840 DK to the nRF52840 dongle

[rmarques]

I tried to follow this guide:

https://devzone.nordicsemi.com/tutorials/b/getting-started/posts/nrf52840-dongle-programming-tutorial?CommentId=fd959c7d-2374-443a-8af7-b4d4f0d35228

To prove the concept of adapting SDK examples from the nRF52840 DK to the nRF52840 dongle.

I am using SEGGER EmStudio 4.12 and I tried either using a nRF52840 DK with a Tag.Connect.com cable assembly connected to the Debug out of this board or the nRFConnect Programmer to program the nRF52840 Dongle.

So, if I understood correctly, we can open the blinky project example of the SDK for the nRF52840 DK located at

SDK_dir/examples/peripheral/blinky/pca10056/mbr/ses/blinky_pca10056_mbr.emProject

Modify some definitions on this project and then program the nRF52840 Dongle, and have the same result as if we opened the project for the Dongle, located at

SDK_dir/examples/peripheral/blinky/pca10059/mbr/ses/blinky_pca10059_mbr.emProject

So these are the fields I modified of the blinky_pca10056_mbr.emProject

c_preprocessor_definitions="BOARD_PCA10059;BSP_DEFINES_ONLY;CONFIG_GPIO_AS_PINRESET;FLOAT_ABI_HARD;INITIALIZE_USER_SECTIONS;NO_VTOR_CONFIG;NRF52840_XXAA;"

linker_section_placement_macros="FLASH_PH_START=0x0;FLASH_PH_SIZE=0x100000;RAM_PH_START=0x20000000;RAM_PH_SIZE=0x40000;FLASH_START=0x1000;FLASH_SIZE=0xdf000;RAM_START=0x20000008;RAM_SIZE=0x3fff8"

The only fields I had to modify were BOARD_PCA10056 to BOARD_PCA10059 and FLASH_SIZE=0xff000 to FLASH_SIZE=0xdf000.

Then I tried to build and run the program on the Dongle but the board just freezes and doesn't do anything. Segger says download successful and nRFConnect says DFU for Application completed successfully!

If I use the blinky project example designed for the dongle it works and I can change the frequency of the LED switching.

What am I missing? Thanks

[awneil]

The nRF52840  chip on the DK and the Dongle is identical; it neither knows nor cares what board it is mounted on - therefore, the same code will run identically on the two.

The difference is in the external hardware - so anything that relies upon the external hardware on the DK which is not on the dongle will not work.

One key hardware element which is present on the DK but not the Dongle is the J-Link programming & debugging interface.

So how have you programmed the dongle?

[rmarques]

I tried programming it with a nRF52840 DK, connected to the board via Debug Out and, in another try, I used the nRFConnect Programmer via USB. Does that answer the question? The blinky example project for PCA10059 works on the dongle.

[awneil]

If you've got the debugger connected, did you use it to see what's happening?

Did you do a full chip erase before programming, and remember to reprogram the SoftDevice?

Because it doesn't come with the on-board JLink, the Dongle has a bootloader - so your code needs to work with that ...

[rmarques]

I only used the debugger to program the Dongle, I may learn about it in the meantime.

I did a full erase yesterday by accident and had to use a JLink-Pro to reflash the Dongle, since the full erase resets the REGOUT0 register, which makes the logic level and VDD 1.8V.

The Blinky example doesn't need a SoftDevice as far as I can tell from the link above (here for convenience). The BLE examples need it, yes, but I am not using them for now.

[awneil]

Yes, you certainly should learn to use the debugger - it should be considered an indispensable part of your tool kit!

https://www.avrfreaks.net/comment/1138166#comment-1138166

You're right about the SoftDevice.

[rmarques]

So, I've successfully connected a J-Link pro debugger to the dongle, programmed it with the blink project example intended for this board and was able to add a breakpoint and stop/go over it normally.

When I made the modifications to the blink project for the PLA10056 that were recommended in the guide, the board was also programmed successfully and I could debug it normally, but the LEDs didn't light up as they should, instead they were turned off always.

I put a breakpoint in the line that switched the LEDs on and off inside the for loop and that breakpoint was reached consecutively as expected. So now I suspect that somehow the LEDs are not mapped correctly when switching board definitions in the c_preprocessor_definitions of the PLA10056 project.

Ideas?