nRF9160 LWM2M sample with Leshan prj.conf setup

[bjull]

I've been trying to run the LWM2M sample from here but I've been running into some issues. Leshan provides two URLs for publicly accessible test LWM2M servers, coap://leshan.eclipseprojects.io:5683 and coaps://leshan.eclipseprojects.io:5684, as described here. I've followed the instructions on the "nRF9160: LwM2M Client" page but I've been unable to connect to the LWM2M server and my client prints this error:

[00:17:17.579,650] <inf> net_lwm2m_rd_client: RD Client started with endpoint 'nrf-{IMEI REDACTED}' with client lifetime 30
[00:17:17.579,772] <err> net_lwm2m_rd_client: Cannot init LWM2M engine (-22)

My best guess is that I'm entering the server URL in the prj.conf incorrectly. I've tried a few different possible combinations but to no avail

CONFIG_APP_LWM2M_SERVER="coaps://leshan.eclipseprojects.io:5684"
CONFIG_APP_LWM2M_SERVER="coaps://leshan.eclipseprojects.io"
CONFIG_APP_LWM2M_SERVER="leshan.eclipseprojects.io:5684"
CONFIG_APP_LWM2M_SERVER="coap://leshan.eclipseprojects.io:5683"
CONFIG_APP_LWM2M_SERVER="coap://leshan.eclipseprojects.io"
CONFIG_APP_LWM2M_SERVER="leshan.eclipseprojects.io:5683"
CONFIG_APP_LWM2M_SERVER="leshan.eclipseprojects.io"

I also have my LWM2M_PEER_PORT set to 5684 if that matters. It could also be possible that my PSK settings are wrong. My config in the Leshan server is as described in the guide (id=Client_identity, PSK=000102030405060708090a0b0c0d0e0f, endpoint=nrf-{IMEI})

Any help to get this sample up and running would be appreciated.

EDIT:

I've checked the modem firmware and it's up to date (1.0.1). I also verified the Leshan demo LWM2M server using a separate LWM2M client running locally and it appears to be working fine as well.

[Øyvind]

Hello, 

I've followed the instructions on the "nRF9160: LwM2M Client" page but I've been unable to connect to the LWM2M server

The only thing that comes to mind, is that in the documentation it to configure prj.config with: 

CONFIG_APP_LWM2M_SERVER="{IP address of LwM2M server}"
CONFIG_LWM2M_PEER_PORT=5684

However, the error message:

[00:17:17.579,772] <err> net_lwm2m_rd_client: Cannot init LWM2M engine (-22)

 "Cannot init LWM2M engine (-22) indicates, according to errno.h, an invalid argument when calling lwm2m_engine_start(). 

Will investigate here.

Kind regards,
Øyvind

[Øyvind]

Hello again, 

I am seeing the same here, and unfortunately, nothing to do at the moment.  Will report as a bug to our SDK team.

Kind regards,
Øyvind

[bjull]

Hi Øyvind,

Thanks for your feedback and flagging to the SDK team. Could you please provide a target date for the resolution of the issue?

Best regards,
Ben

[Øyvind]

Hi Ben, 

I'm sorry, but no target date available yet. Will keep you posted.

Kind regards,
Øyvind

[Achim Kraus]

There maybe many reasons for that, but one, which occurred frequently over the years, was the encoding of the PSK secret. Leshan supports hex to enable access to a full binary secret. Other just use the ASCII string direct as secret. To check that, change the secret in the client to "0123456789ABCDEF" and on leshan to "30313233343536373839414243444546". Good luck :-).