External nRF52840 board appears to flash but won't do anything

[ZacMid007]

I'm attempting to develop for the xiao_ble board in nRF Connect, programming it as an external board using the nRF52840 development kit and the Seeed XIAO expansion board to access the relevant pins. I have the wiring set up like so:

And it appears to work, I see it programming the flash, verifying, etc, and the XIAO board is no longer recognized by the Arduino IDE so *something* is happening, but I can't get it to even a blink a simple LED; it won't show up as a COM port or do anything it should be doing. Am I missing something? The example I'm trying to start with as a base point is zephyr/samples/basic/blinky

[Jared]

Hi,

1. Have you connected the serial interface of the custom board to your computer? Since you expect it to show up as a COM port?
2. Can you share the log output when you flash the board?
3. Have you tried using the NCS VS Code extension instead of Arduino IDE?

regards

Jared

[ZacMid007]

Hi Jared,

1. Yes, when attempting to discover the board as a COM port I connect it via its USB-C connector; out of the packet, the board registers as a COM port when connected this way, I guess because of the Arduino bootloader it ships with.

2:

3: Yes, that is what I am using to develop and flash the board; I only used the Arduino IDE to initially verify the board was working.

[Jared]

Hi,

The log from the programming doesn't really output any errors so it seems like everything is fine from the programming perspective. What is actually happening on the custom board is difficult to say as I don't have any experience with it. 

ZacMid007 said:

and when I first checked the device using Arduino in the initial test, it blinked fine when powered from the expansion board/connected as shown.

Can you elaborate on this? Have you been able to flash the board with the blinky example before and see that the LEDs on the board starts blinking? Are you still able to repeat this result?

regards

Jared?

[ZacMid007]

No, the initial blinking was only from the Arduino sketch/flash before attempting to use nRF Connect. After flashing from nRFC, I am unable to further program using Arduino and the previously working program appears to be erased.

[Jared]

Hi,

I think it would better if you contacted the creators behind this board as it's a third-party board. From the Nordic side, I can't say that I see any signs of error since the programming verifies that it was successfully flashed. 

regards

Jared

[ZacMid007]

I had a look using the nRF Programmer, and the two build files for the boards appear very different; this is the blinky build file (zephyr.hex) for the xiao_ble

Whereas this is the blinky zephyr.hex file for the dev kit, which runs successfully on said dev kit:

I have also made a post on the Seeed forum about this

[Jared]

Hi,

This is the memory layout from building blinky for my nRF52840 devkit:

Which is similar to the last one you've shared.

ZacMid007 said:

his is the blinky build file (zephyr.hex) for the xiao_ble

Looks like the application expects something else to be flashed at the beginning of flash. Looking at the dts file of the board, it looks like the board expects the softdevice from nRF5SDK to be flashed: 

It seems to me that this board was originally made for the nRF5SDK. Can you clarify whether this is correct with the creators of the board?

Also, you can try to build and flash the application to the board without 

CONFIG_BUILD_OUTPUT_UF2=y

CONFIG_USE_DT_CODE_PARTITION=y

 

Which are defined in the board config. 

 

regards

Jared

[ZacMid007]

Changing those 2 parameters worked! Thanks for your help :)

[Jared]

Nice,

I'm happy that it worked for you!

regards

Jared 

[Droidik]

Thank everyone for solving it. This bugged me for a whole day and the only change I did was update the Zephyr version. This should be mentioned in the docs, because the default behavior has changed between Zephyr versions.