Re: LWM2M client to nrf582540-DK #nrf52840 #networking

Lubos, Robert

Hi Nikos,


If you use CONF_FILE option, you need to specify both, prj.conf and the overlay: “-- -DCONF_FILE="prj.conf overlay-usb-nrf-br.conf"”.

There’s also an OVERLAY_CONFIG option, where you can specify only the overlay file: “-- -DOVERLAY_CONFIG= overlay-usb-nrf-br.conf”.


Regarding OTBR, I’m sorry but I don’t have a working setup right now to test. For sure it’s critical that you provide the OTBR with the same channel/panid/network key as other Thread devices in your network.

The easiest way to determine whether you are connected to other devices is to use OT CLI component (OPENTHREAD_SHELL needs to be enabled, it is by default) and check children/router tables:

  • “ot role” to determine whether you are a router (leader in specific case) or a child
  • “ot child table” to see if you have any children in router role
  • “ot router table” to see if there are any other routers in your network
  • “ot parent” to see information about a parent router in child role


I haven’t worked with OTBR for some time, but I’m not sure if using “Join” option will work unless you have a commissioner in your network. I think that safer option would be to let the border router form the network ( ) and then let your other device join it. Just make sure to use the same network parameters, as mentioned earlier.





From: users@... [mailto:users@...] On Behalf Of Nikos Karamolegkos via
Sent: Friday, September 4, 2020 13:05
To: users@...
Subject: Re: [Zephyr-users] LWM2M client to nrf582540-DK #nrf52840 #networking


I am a bit lost.  I am trying to compile the OpenThread NCP sample in order to connect the nrf52840 dk with the raspberry which will be running the openthread border router docker image. In order to compile the sample I am running west build -b nrf52840dk_nrf52840 samples/net/openthread/ncp/ -- -DCONF_FILE="overlay-usb-nrf-br.conf" but I have to add CONFIG_UART_INTERRUPT_DRIVEN=y in the overlay file (otherwise I have errors). Is this a bug? Nevertheless, finally, when I am using the pre compiled image from openthread site for the nrf52840-dk and at the same time I have a node running the LWM2M sample with the default overlay-ot.conf file (from the echo client) I can see the network in the OTBR GUI. I am trying to join the network from the OTBR but I don't know how to continue (or to check if the procedure is successful)  . Is the OTBR configured ok? Have anybody experience running the the LWM2M client over OT using the border router? I will appreciate some help.

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