How to set node as child role in OpenThread?

[Roger]

Hi All,

At the moment, I have three nodes and would like to configure one node as an end-device and the other two as routers. Using CoAP, the simple_coap_server is used for the router nodes and the simple_coap_client is used for the end-device node. The problem is that the end-device node changes state to a router after a certain time. I don't understand why this is happening. I also tried factory reset the nodes but the state still changes for the end-device after the thread start command. How does one set a node in the network as an end-device without its role changing state?

child state change.png

Best regards,

Roger

[Jørgen Holmefjord]

Hi Roger,

You can use the function otThreadSetRouterRoleEnabled() to disable or enable the router role in a Full Thread Device (FTD).

You can also enable or disable the router role using the CLI command routerrole.

Best regards,

Jørgen

[Roger]

Hi Jørgen,

Very helpful, thank you! I tested it and it works. I'm still getting around the API functions.

I've been wondering, if I want to send a message to a specific router address, will the CLI command coap client work with the API? I tested it but it seems to give me an error.

Roger

[Jørgen Holmefjord]

Which error does it give? Have you enabled the coap server on the receiving node using coap server, and set a URI string for the resource using coap server name before calling coap client?

[Roger]

I get an 'Error 6'. On the server receiving node, when I enter from the CLI coap server start, I also get an 'Error 6'.

[Jørgen Holmefjord]

Which version of the Thread SDK are you using? I see that the CoAP server/clients were first added to the OpenThread repository on April 11., so it is not available in nRF5 SDK for Thread v0.8.0. It should work with nRF5 SDK for Thread v0.9.0.