Nrfutil dfu over ble causes ble device to disconnect

[cheeetoo]

I am using bleak and python to connect to a ble device and then using subprocess to run the dfu. The ble device disconnects when the dfu starts and then I get "Connection Failure - Device not found" error. I am using the nrf52833 board as a connectivity device.

[Einar Thorsrud]

Hi,

That error indicates that the device (which is in bootloader mode) is not found. Have you specified a name (using the -n option) or an address (using the -a option), and double checked that it is correct?

[cheeetoo]

Yes, I have tried specifying both and I get the same result.

[Einar Thorsrud]

Can you show the full command you are using, and perhaps also a screenshot of the device seen from nRF Connect for Desktop Bluetooth, so that I can see both the name and BT address of the device you are trying to update?

[cheeetoo]

The command I am using is "nrfutil dfu ble -ic NRF52 -pkg /home/finn/Downloads/firmware.zip -p /dev/ttyACM0 -a {d.address} -f'. {d.address} is the address of the device provided by bleak.

[Einar Thorsrud]

I don't have experience with bleak, but different tools can show the address with different endianness. Can you try to swap the endianness and see if that helps?

[cheeetoo]

The endianness definitely isn't the problem because I am using the same address to connect to the device. Also I should probably mention that I am not getting an error, it shows a status bar at 0% and then the device disconnects and my program hangs for a second and then crashes.

[Einar Thorsrud]

cheeetoo said:

The endianness definitely isn't the problem because I am using the same address to connect to the device.

Using nrfutil? If not, it would make sense to spend extra 10 seconds to swap the address manually just to double-check.

The error "Connection Failure - Device not found" is printed only when a connection failed to be established (see how verify_stable_connection() is implemented and used), so there is some reason the connection is never established. The typical reasons for that are:

• The specified address (if any) is wrong
• The specified name (if any) is wrong
• The device is not advertising / not connectable

I cannot say much more at this point, but as mentioned, I would think it would be useful to see the device advertising in for instance nRF Connect Bluetooth, as that would give us some key information (first of all that it really is advertising and the address).