DFU mode and BLE

[Roei]

Hi,

I have some questions regarding DFU:

• Does it have its own BLE hardware?
• Does it have its own processor? Or it's part of the main one?
• Can we synchronize between our main process and DFU process?

Thanks!

[Roei]

I will try to focus my question:

After reset my application to enter DFU mode, I can still see advertisement on my PC scanner.

Does it make sense?

Thanks!

[Vidar Berg]

Hi,

Yes, this is expected if you're using the Bluetooth bootloader from the nRF5 SDK, but it should advertise with a different address and name compared to the application, see Buttonless Secure DFU Service without bonds for more details.

Best regards,

Vidar

[Roei]

Thanks!

Is it possible that the scanner will see both advertisements at the same time? Main app and DFU app? Or main app advertisement while DFU is already connected?

[Vidar Berg]

No, it's not possible to see adv. from both app and bootloader. The device can only run one program at a time. If you see advertising from the application, then that indicates the the bootloader did not enter DFU mode.

Assume you see the bootloader advertising if you delete the app from your device?

[Roei]

After the main app is connected, it set bootloader flag and reset itself. After that - bootloader is active and main app advertisement is active as well, according to the scanner

[Vidar Berg]

The app advertising may be cached from a previous session, or does the RSSI (signal strength) of keep getting updated when you are supposed to be in DFU mode?