Trouble with BT840 and nRF5 SDK ble_app_uart example

[Eivinhj]

Hi, 

I'm quite new to the nRF environment and am trying to run one of the nRF5 SDK examples (ble_peripheral -> ble_app_uart -> pca10056 -> s140) on a custom bord with BT840 (nrf52840). Instead of being initialized properly, the device is shown in the nRF Connect app as "dfutarg". It seems like it get stuck somewhere in initialization of the softdevice(?). I have commented out the  buttons_leds_init(&erase_bonds) in main since it is not a nRF52840-DK. 

I have included an external 32kHz crystal and capacitors on the PCB and also tried the solution as suggested in https://devzone.nordicsemi.com/f/nordic-q-a/58956/softdevice-not-working-on-bt840-based-custom-board with no luck.

Also, when I flash the example hex file provided by Fanstel it is working properly, so I don't think it's a hardware problem.

SDK v17.0.0

S140 Softdevice

BT840 datasheet: https://www.fanstel.com/s/BT840F_datasheets-tar9.pdf 

Im running Segger Embedded Studio for ARM v.4.52c, but have also tried with arm-gcc-none-eabi

[Turbo J]

Eivinhj said:

Instead of being initialized properly, the device is shown in the nRF Connect app as "dfutarg".

That is the bootloader.

If you want to run/debug an application with a bootloader installed, generate the bootloader settings page with nrfutil and flash it, too.

Other workaround: Completely erase the chip including UICR.

[Eivinhj]

Thank you for the quick reply!

I generated a bootloader with "nrfutil settings generate --family NRF52840 --application ble_app_uart_pca10056_s140.hex  --application-version 3 --bootloader-version 2 --bl-settings-version 2 settings.hex" and flashed it. It works!