Unable to connect/flash Adafruit Feather nRF52840

RE: Unable to connect/flash Adafruit Feather nRF52840

Vidar Berg — Mon, 05 Sep 2022 12:47:19 GMT

Hello,

The USB interface will only show up if the OT application is running properly on your device, so I would suggest you try to debug the application to confirm this. As a start, please run "nrfjprog --readregs" after having programmed the FW hex with nrfjprog --program <path to hex file> --reset. This will show us if the program may be stuck in a fault handler or not.

RE: Unable to connect/flash Adafruit Feather nRF52840

fklement — Fri, 02 Sep 2022 13:04:46 GMT

I compiled OT with USB CDC ACM support.
```
UF2 Bootloader 0.7.0 lib/nrfx (v2.0.0) lib/tinyusb (0.12.0-145-g9775e7691) lib/uf2 (remotes/origin/configupdate-9-gadbb8c7)
Model: Adafruit Feather nRF52840 Express
Board-ID: nRF52840-Feather-revD
Date: Jul 13 2022
SoftDevice: S140 6.1.1
```

RE: Unable to connect/flash Adafruit Feather nRF52840

fklement — Fri, 02 Sep 2022 11:53:25 GMT

We have now managed to flash the files normally with the nrfjporg and a j-link debugger.
But after flashing the .hex file, the device can no longer be found in the /dev/tty.* devices.

Do you happen to have an idea/guess what we are doing wrong here?

RE: Unable to connect/flash Adafruit Feather nRF52840

Vidar Berg — Tue, 30 Aug 2022 13:08:16 GMT

Hello Felix,

Could it be that the openthread FW is not linked to the correct start address? I'm not sure if the UF2 bootloader allow you to ovewrite the Softdevice (Memory Map). If it doesn't, then you have to make sure the OT FW start at address 0x26000 in FLASH, and at 0x20000008 in RAM.

RE: Unable to connect/flash Adafruit Feather nRF52840

fklement — Tue, 30 Aug 2022 12:26:36 GMT

Hello Vidar,

Yes, we have already discovered that nrfjprog requires a J-Link debugger.
We have also tried the possibility with the UF2 bootloader, but unfortunately without success at the moment.

Nevertheless, thank you for your quick answer.

LG,
Felix

RE: Unable to connect/flash Adafruit Feather nRF52840

Vidar Berg — Tue, 30 Aug 2022 11:18:51 GMT

Hello,

nrfjprog requires a J-link debugger to program the device. The other alternative if you don't have a debugger, is to try program the FW through the bootloader that adafrauit has put on the chip. I see their UF2 bootloader mentioned here: https://learn.adafruit.com/introducing-the-adafruit-nrf52840-feather?view=all#update-bootloader-use-uf2 supports drag&drop programming.

Best regards,

Vidar

RE: Unable to connect/flash Adafruit Feather nRF52840

fklement — Tue, 30 Aug 2022 07:00:19 GMT

I've forgotten under which operating systems we tried this:

Currently under MAC OS and yesterday also under Linux Ubuntu.