building at_client for nb-iot on nrf9160-dk

[paul_tanner]

select at_client folder

west build -b nrf9160dk_nrf9160ns -p

shows this warning

```

warning: The choice symbol LTE_NETWORK_MODE_NBIOT (defined at
/Users/paul_tanner/Nordic/nrfsrc/ncs/nrf/lib/lte_link_control/Kconfig:152) was selected (set =y),
but no symbol ended up as the choice selection. See
docs.zephyrproject.org/.../CONFIG_LTE_NETWORK_MODE_NBIOT.html and/or
look up LTE_NETWORK_MODE_NBIOT in the menuconfig/guiconfig interface. The Application Development
Primer, Setting Configuration Values, and Kconfig - Tips and Best Practices sections of the manual
might be helpful too.```

```

paul_tanner@iMac at_client % ls

CMakeLists.txt build_nrf9160dk_nrf9160

README.rst build_nrf9160dk_nrf9160ns

at_client.hex prj.conf

at_client_nbiot.hex sample.yaml

build src

```

note there is no Kconfig file here

when running the resulting binary

```

AT%XSYSTEMMODE?
%XSYSTEMMODE: 1,0,1,0

```

Not surprisingly it does not connect to any NB-IOT access point.

My questions are:

1. do I need a Kconfig for NB-IOT?

2. can I use the same firmware versions for this and LTE/M?

Thx. 

[Didrik Rokhaug]

From your last log, it looks like you are able to connect:

+CEREG: 5,"1BE8","0029FF0B",9,,,"11100000","00101000"

[00:02:01.242,523] [0m<inf> asset_tracker: Network registration status: Connected - roaming[0m

Although the DNS lookup failes:

[00:02:01.719,909] [1;33m<wrn> date_time: getaddrinfo, error: -11[0m

[00:02:03.655,975] [0m<dbg> nrf_cloud_transport.nct_connect: getaddrinfo failed -11[0m

It might be that the network does not support ePCO. At least, that has been the case in other NB-IoT networks with DNS problems.

You can use "legacy" PCO instead by setting CONFIG_LTE_LEGACY_PCO_MODE=y

[paul_tanner]

Thanks. That certainly moved things forward.  So now it does get data/ time.

We then found a whole lot of other issues which I have posted separately.

devzone.nordicsemi.com/.../initiation-problem-on-vodafone-with-nb-iot-from-nrf9160-dk