nRF9160 MQTT NB connect LTE failed

[LeoChen]

Hi

After upgrade modem to mfw_nrf9160_1.0.0.

Most of our SIM cards still working good on both AT and MQTT projects.

Two of our SIM cards can't connect to LTE when uses MQTT default project.

These two SIM still can connect to LTE when uses AT command project.

These two SIM is used NB1.

I need to setup AT%XSYSTEMMODE=0,1,0,0 when using AT project.

The AT%XSYSTEMMODE=0,1,0,0 return error when use MQTT project.

And I also do not want to use AT host mode in my MQTT project.

Would you please tell me how to use these SIM cards to connect LTE when use MQTT project.

DK: PCA10090 V0.8.5

Modem: mfw_nrf9160_1.0.0

nRF connect SDK: v1.0.0

Regards,

[Bjørn Kvaale]

What you want to do is either set the XSYSTEMMODE command in the code itself, similar to how the asset tracker does this, or set the following in the prj.conf file for your project:

CONFIG_LTE_NETWORK_MODE_NBIOT=y

This should automatically set the mqtt example to nB-IoT. You can then check using the Link Monitor to see if the XSYSTEMMODE has been set correctly. Also, make sure to open the project in a new build folder after you save the changes to the prj.conf file. Otherwise, it may not switch to nB mode.

Which error do you receive when setting XSYSTEMMODE in MQTT project?

[LeoChen]

Thanks, the CONFIG_LTE_NETWORK_MODE_NBIOT=y is working.

The AT command setting XSYSTEMMODE in MQTT project also working.