DFU doesn't work in nRF Connect app

[Marta L]

Hello all:

I've developed an nRF52810 application based on the Blinky example. It includes buttonless DFU support and i'm able to update the firmware by an nRF52 dev kit + PC (nRF Connect for Desktop). However, when I try to do the same process with a mobile phone (app nRF Connect) I get an error. I'm using SDK 17.0.2, SD 112 7.2.0

I'm doing the following steps:

Connect to the board I want to update -> DFU -> Select file type: Distribution packet (ZIP) -> Drive ->  select zip file.

It starts DFU but I get "Error  (0x8): GATT CONN TIMEOUT"

Does anyone know why it is happening?

Many thanks in advance,

Marta

[Marta L]

Hello,

I've tried exactly the same process with other mobile phones and DFU works. Could it be related to the Bluetooth version? The one that doesn't work has v4.2 and the ones that work 4.1 or 5.0.

Moreover, when DFU is done by PC+nRF dev kit, the device starts advertising after update, but when it is done from the mobile app, i have to reset the device to start advertising. Any solution for the mobile case?

Thanks,

Marta

[Vidar Berg]

Hello Marta,

It should not be related to Bluetooth version at least. Can you post the full DFU log of when it fails? And also let me know whether you are disconnecting the link from the DFU callback in your application or not.

Best regards,

Vidar

[Marta L]

Hi,

Here you can see the full log:

I've added the code for disconnecting the connection in the DFU callback as you suggested, but it still doesn't work. 

[Vidar Berg]

Hi,

Interesting that it keeps loosing the connection over and over again. Maybe there is an interoperability issue with this particular phone. What make and model is it?

Would you be able to provide a sniffer trace (nRF Sniffer for Bluetooth LE) of when it fails? That may help us confirm the issue.

Thanks,

Vidar