Perform NRF52840 OTA over the NRF9160 and UART

[Hash5422]

Hello, 

I am developing a BLE - LTE sensor gateway using the NRF9160DK.

I have written code for OTA updating the 9160 chip over LTE, but I am not sure how to update the NRF52840 side. Both those chips are connected via UART so I am guessing performing an OTA over UART for BLE would be the best approach but I am not sure how to go about it. 

Are there sw examples for these? I read a few related tickets on DevZone but they weren't super clear, could you provide the right documentation to get me started as well? 

[Elfving]

Hello Harshil,

How to proceed with this depends a bit on what you want to do. 

Both those chips are connected via UART so I am guessing performing an OTA over UART for BLE would be the best approach but I am not sure how to go about it. 

Am I understanding you correctly, in that you want to do the DFU on the nRF52840 by getting the image from the 91 over UART? That is an understandable approach.

Unfortunately I don't think we have any samples that demonstrate this. The few tickets you find on DevZone about it is essentially what is available, though it is theoretically possible. I believe there is work being done on getting some example for this available at some point though. I could ask around about this for you if you want me to, though in any case there is currently no sample nor any documentation about this.

Regards,

Elfving

[Hash5422]

Hey Elfving, 

Elfving said:

Am I understanding you correctly, in that you want to do the DFU on the nRF52840 by getting the image from the 91 over UART? That is an understandable approach.

Yes, that's exactly what I'm trying to do. Could you ask internally and let me know. Any information is helpful! 

I found this forked patch on github - https://github.com/nrfconnect/sdk-nrf/commit/6baf0e006299bb69152cf3fb7e690985cdcbcb3b 

Do you think this is usable? 

[Elfving]

Yes. After asking around that is also the go to example for it. It is written for a rather old NCS version unfortunately, though it has been updated to NCS 1.4. (Look here and at the patch here.)

So you might want to update it, and you are unfortunately on your own for a large part of this. 

Regards,

Elfving

[Hash5422]

So does this also mean my NRF52840 code should also be Zephyr based? 

In my project, I use a zephyr based project on nrf9160 and an SDK17 Softdevice based project on the bluetooth side, should I port my project to Zephyr to be able to use this example? Also, I don't see any nrf52840 based files in his commit, so that's the heavylifting I have to do, correct? Just want to make sure I understand the complexity of this so I can predict my timelines. :) 

[Elfving]

The nRF52840 code could potentially be nRF5 SDK based. The 52 should be programmed with the hci-lp-uart sample. 

What you need to do should be here in the readme. 

Regards,

Elfving