How to change nRF9160's default modem firmware from M1 to NB1

[bbslhb]

According to at client demo, LTE-M1 is the default mode in firmware mfw_nrf9160_0.7.0-29.

Modem work mode will be LTE-M1 after every reset even you changed to NB1.

I can change to NB1 in at client demo but modem will work with LTE-M mode on any other demos.

LTE-M1 is not available in my country so I can't debug LTE function.

Is there any way to change default work mode from LTE-M to NB1?

[Martin Lesund]

Hi Li,

You can set the network mode as described in the documentation.

[bbslhb]

Hi Martin.

I enterd this link and got the official answer that the default mode will be LTE-M after reset or power lost and can't be changed.

You must use CONFIG_LTE_NETWORK_MODE_NBIOT to manually change the mode at your app code If you want to use NB-Iot.

Thank you.

[jbrzozoski]

Further down in that link, it also says this:

If the modem is shut down gracefully before the next boot (by using AT+CFUN=0), it keeps the current setting.

That's not very explicit, but what it's trying to say that the current setting of AT%XSYSTEMMODE will also be saved to NVM by doing AT+CFUN=0, which will change the value used by default on power up.

[bbslhb]

Hi, jbrzozoski:

I tried AT+CFUN=0 and it saved MODE settings.

I tried AT+CFUN=1 and AT+CFUN=4 but didn't try AT+CFUN=0 and that's why I ask here.

MODE setting can be saved so I don't need to change code. I can use the old bin file generated 3 months ago to test this new firmware.

Thanks for your answer.