AWS FOTA for nRF52840

[raferrarezi]

Hi,

We are developing an asset tracker using nRF52840 and a Telit modem.

Is it possible to use AWS FOTA library (AWS jobs + FOTA download) to do the application firmware update 'based' on the nRF9160 example?

We already established MQTT connection using the PPP interface of the modem.

I'm asking because I was in doubt about the use of "Modem and Trusted Firmware-M" libraries for the nRF9160 and the nRF52840 DFU support not being uart, usb or ble.

The development setup is:
- MCUBoot
- NCS/Zephyr SDK v2.x.x
- External Flash for the update

Any guidance is welcome ;)

[Charlie]

Hi Rafael,

It is more practical to use the manner Cloud--LTE--> LTE Chip/Module(nRF9160/Telit Modem)--Firmware Upgrade Over UART--> nRF52840 instead of running FOTA tasks management on nRF52840.

Unfortunately, we do not have an official sample for Cloud--LTE--> LTE Chip/Module(nRF9160/Telit Modem)--Firmware Upgrade Over UART--> nRF52840, but you can find some references from the following links:

(+) Firmware Update OTA of nRF9160 by BLE nRF52840, , , , and update nRF52840 by FOTA of nRF9160 ? - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com)

(+) DFU (FOTA) of the nRF52 devices using the nRF91 LTE gateway - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com)

Best regards,

Charlie

[raferrarezi]

Hi Charlie,

I'd seen these links among others to try to figure out.

As we already have the MQTT connection, I thought of just changing the flash writing routines. But here comes the doubt of how to integrate with the MCUboot, SMP and DFU. I'm not that familiar with NCS.

We can not add the "controller" to the Telit modem btw.

If you can clarify anything else I would be grateful.

Best regards,

[Charlie]

Hi Rafael,

This is currently no ready-to-use solution for your request. Even though I know something about NCS, I do not feel confident that your proposal will work.

1) The current FOTA solution on nRF9160 is closely related to the modem inside nRF9160, so it is not easy to port libraries like AWS FOTA library directly for nRF52840.

2) The firmware update needs cooperation on both nRF52840 and the host side. If the Telit modem has a fixed design, it is not easy to make the solution work. 

3) Downloading firmware with MQTT is not a good idea, since it is mostly for message transmission, so it is not effective to transfer a bigger size file like firmware. nRF9160 use HTTP/HTTPS for firmware downloading.

The previous suggestions are what I think may work for your application requirement. There is still much effort that needs to be done if you need a robust nRF52840 FOTA over LTE solution.

Best regards,

Charlie

[raferrarezi]

Oh yes, the download itself should be HTTP/HTTPS.

[raferrarezi]

Hi Charlie,

I managed to make it work.

Now we need to encrypt the update file.

I could not find an example how to encrypt the app_update.bin

And about the prj.conf of the mcuboot should look like this?

CONFIG_BOOT_SIGNATURE_TYPE_RSA=y

CONFIG_BOOT_ENCRYPT_RSA=y

CONFIG_BOOT_SIGNATURE_KEY_FILE="path_to_pem_file"

CONFIG_MCUBOOT_ENCRYPTION_KEY_FILE=="path_to_pem_file"