"lte_lc: Could not send AT command, error" with nRF9160 SIAA B1 on Custom Board Using SDK v2.5.0 and Modem v1.3.5

RE: "lte_lc: Could not send AT command, error" with nRF9160 SIAA B1 on Custom Board Using SDK v2.5.0 and Modem v1.3.5

ksksue — Mon, 30 Sep 2024 14:59:28 GMT

Yes, it uses LTE-M.
CONFIG_LTE_NETWORK_MODE_LTE_M=y solved the issue.
Thank you for your prompt response.

RE: "lte_lc: Could not send AT command, error" with nRF9160 SIAA B1 on Custom Board Using SDK v2.5.0 and Modem v1.3.5

Øyvind — Mon, 30 Sep 2024 11:59:18 GMT

Hello,

Looking at the error this seems to be an issue with the system mode, where the AWS IoT samples is trying to configure system mode to something else than LTE-M? What happens if you use CONFIG_LTE_NETWORK_MODE_LTE_M=y in your prj.conf?

Kind regards,
Øyvind

RE: "lte_lc: Could not send AT command, error" with nRF9160 SIAA B1 on Custom Board Using SDK v2.5.0 and Modem v1.3.5

ksksue — Mon, 30 Sep 2024 02:54:46 GMT

I made a small modification to the aws_iot sample to comment out sections that caused AT command errors with lte_lc and prevented repeated reboots.
Additionally, I set CONFIG_AT_HOST_LIBRARY=y to enable AT command responses.
However, when I tested it, the AT command errors still appeared as shown below:

*** Booting nRF Connect SDK v2.5.0 ***
[00:00:00.253,417] <inf> aws_iot_sample: The AWS IoT sample started, version: v1.0.0
[00:00:00.253,448] <inf> aws_iot_sample: Bringing network interface up and connecting to the network
> AT
[00:00:07.959,197] <err> at_host: Error while processing AT command: -1
AT> AT
[00:00:16.997,100] <err> at_host: Error while processing AT command: -1
AT

I also tested the aws_iot sample using modem version 1.3.6 with SDK version 2.5.3 on the SIAA board,
but the results were the same as with modem version 1.3.5 and SDK version 2.5.0.