Hello,
I am evaluating the nRF9161 and nRF9151 and have a few questions.
1. In regard to modem FOTA delta firmware updates, where is the delta file stored in both Serial LTE modem (SLM) and non-SLM cases? Is it stored in the modem core flash, or must it be stored in the application core flash or external flash? I have read conflicting information on the DevZone regarding this.
2. When updating to a new modem major firmware version in non-SLM mode via FOTA, say 1.3.x to 1.4.x, this requires a "full" modem firmware update and requires storing the firmware file in external flash due to its size. If you design a product without an external flash, is it true you are then stuck on whatever major version you program and deploy the modem with since you cannot perform a "full' firmware update? Ie, if you are on 1.3.x you can never go to 1.4.x via FOTA?
3. When the modem is used as a Serial LTE modem (SLM), does the modem only support delta firmware updates, or can you also perform a full modem firmware update? If it doesn't support full modem firmware updates in this mode, then are you stuck on whatever modem major version you deploy your product with?
4. Based on the nRF9160 modem firmware compatibility matrix linked below, newer modem firmware versions are not compatible with older versions of the nRF connect SDK. Is this true?
For example, if you are on modem firmware 1.3.1 and nRF Connect SDK 2.0.0, it doesn't seem like you can jump directly to modem firmware 1.3.6 because it isn't compatible with nRF Connect SDK 2.0.0. It seems like you you can only jump to modem firmware 1.3.2 because 1.3.3 isn’t compatible with nRF Connect SDK 2.0.0. Once you jump to modem firmware 1.3.2, you then update to nRF Connect SDK 2.1.0. This will then let you update to modem firmware 1.3.4 (skipping 1.3.2). Then you can update nRF Connect SDK to 2.2.0, which will then let you update the modem firmware to 1.3.6.
Are these incremental updates really necessary?
https://infocenter.nordicsemi.com/topic/comp_matrix_nrf9160/COMP/nrf9160/nrf9160_modem_fw.html
Edit: I have a bonus question not related to FOTA. Please let me know if I should create a new post for this.
5. Do the Nordic cellular modules support multiple carriers with a single eSIM or SoftSIM? If so, how do you add carrier profiles to each SIM type and switch between profiles? I didn't see any AT commands detailing this.
Thanks,
Derek