Modem firmware updates via serial interface

[Johan-Henry]

Good day

We are currently working with the nrf9160 and using it as a serial modem via AT commands by loading the serial_lte_modem application. I am currently investigating the implementation of modem firmware updates (the zip package) in the field and see that a few options exists as described in the documentation. For our application, updating the modem via its serial interface from our main processor would work best, as described in https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/libraries/dfu/fmfu_mgmt.html, but it seems that this implementation cannot co-exist with the serial_lte_modem application. I am quite new to Zephyr and the Nordic build environment, so not sure if there is a simple way to add an AT command to activate the fmfu_mgmt application, placing the modem in an upgrade mode, reboot when done to the usual AT command mode? Not sure if there is a better way to approach the problem? Any guidance would be appreciated.

Thanks

[Naeem Maroof]

Hi Johan, I forgot to mention that I built it for nCS v2.0.0.

I just created new free-standing application and chose serial-lte-modem application.

First built it for the 9160DK (ns). Next, added:

CONFIG_MCUMGR_SMP_UART=y

to the prj.conf, and did the pristine build.

[Johan-Henry]

Just adding CONFIG_MCUMGR_SMP_UART=y does not achieve anything according to this error message as it has other dependencies. If I add CONFIG_MCUMGR=y as well the build fails

[Naeem Maroof]

Hi Johan,

I see it now. 

I will look into it and will update you accordingly.

[Naeem Maroof]

Hi Johan,

Please add following lines at the end of your proj.conf and do a pristine build.

CONFIG_UART_0_INTERRUPT_DRIVEN=n
CONFIG_MCUMGR_SMP_UART=y
CONFIG_MCUMGR=y

Regards,

Naeem

[Johan-Henry]

Thanks Naeem.

Yes, by adding CONFIG_UART_0_INTERRUPT_DRIVEN=n the solution compiles now, but the AT command interface is broken and the modem does not respond to the serial AT commands. Is there any way to get upgrades over serial working without breaking the AT command interface?

Regards

Johan-Henry