In place FOTA through BLE with nrf Connect SDK and Zephyr.

[JacekS]

Hi, I am developing BLE beacon application on the nrf52820 soc which has limited Flash resources. I want to have the FOTA through BLE abilities built in to enable firmware updates in the future. Internally we found some conflicting information on the ability to do an in-place FOTA with just one partition slot - which is better for us as it gives more flash for the actual app than a two-slot update. We are using NCS 2.7.0 and Zephyr, can someone advice if one-slot update is possible with our setup? If not, are there any plans to enable this feature, if so when could we expect this to be available? 

Thanks!

[tesc]

Hi,

Single slot DFU is only available for serial DFU, and not for BLE OTA DFU. The reason for this, is that serial capabilities (such as UART or USB) are relatively light weight, and can be part of the bootloader. BLE on the other hand is a much larger stack, and so for BLE OTA DFU you do need the application for downloading the new firmware. Therefore, you do need two slots for BLE OTA DFU. You can however have the second slot in external Flash, if the on-chip Flash for the nRF device is not sufficient for your application needs.

Regards,
Terje