This example application demonstrates a LWM2M 1.1 client running on a Thread node. It uses the OpenThread CLI to drive the demonstration, with custom commands to drive the LWM2M functionality.
Further information about LWM2M can be found in the LWM2M Core Specification and the LWM2M Transport Specification. This example includes support for the CoAP over UDP and CoAP over DTLS transport bindings.
In order to run this demonstration, a Thread border router, such as the Cascoda evaluation border router is required. The border router should be upgraded to the latest version using the scripts available here.
Please see the evaluation guide for more information on how to use this binary. The guide also includes some considerations for use in practice.
Note that if secure LWM2M is required (using DTLS), the CASCODA_BUILD_SECURE_LWM2M must be enabled in the CMake config.
In addition to the standard OpenThread CLI commands, which are documented here, the following are also implemented, as extracted from the wakaama demo.
Start the LWM2M Client stack, bootstrapping or directly connecting to a server as required. This function takes arguments in POSIX style.
| Option | Description |
|---|---|
| -n NAME | Set the endpoint name of the Client. Default: testlwm2mclient |
| -l PORT | Set the local UDP port of the Client. Default: 0 (ephemeral) |
| -h HOST | Set the hostname of the LWM2M Server to connect to. |
| -p PORT | Set the port of the LWM2M Server to connect to. Default: 5683 for coap://, 5684 for coaps:// |
| -t TIME | Set the lifetime of the Client in seconds. Default: 300s |
| -b | Bootstrap requested. |
| -c | Change battery level over time. |
| -i STRING | Set the device management or bootstrap server PSK identity for PSK security. Example: -i examplepskidentity |
| -s HEXSTRING | Set the device management or bootstrap server Pre-Shared-Key for PSK security. If not set use non-secure mode. Example: -s aabbccddeeff0011223344556677889900 |
Start the LWM2M client without security, name ‘cascoda-client’, connecting to a server running on the adjacent LAN network:
lwstart -n cascoda-client -h fdaa:bbcc:ddee:0:a196:ec9a:66bc:f69
Note: Running without security - of course - offers no end-to-end security, so is a poor choice for almost all applications.
Start the LWM2M client, with endpoint name ‘cas-test’, connecting to the server at ‘leshan.eclipseprojects.io’ with identity 0123456789 and preshared secret key 00112233445566778899
lwstart -n cas-test -h leshan.eclipseprojects.io -i 0123456789 -s 00112233445566778899
Note: The identity and PSK must be pre-configured on the server or this will fail with security error.
Start the LWM2M client, with endpoint name ‘bootstrap-test’, connecting to the server at the given IPv6 address (Server running on local network in this case), port 5784, identity 9879879878, preshared secret key aabbcc334488227755009911:
lwstart -b -n bootstrap-test -h fdaa:bbcc:ddee:0:a196:ec9a:66bc:f69 -p 5784 -i 9879879878 -s aabbcc334488227755009911
Note: The identity and PSK must be pre-configured on the bootstrap server, and the bootstrap server must be configured to bootstrap the client with URI and credentials that are valid for the server that it will register to.
Stop the LWM2M client from running.
List the configured servers and their states.
Example:
> lwlist
Bootstrap Servers:
- Security Object ID 0 Hold Off Time: 1 s status: DEREGISTERED
LWM2M Servers:
- Server ID 123 status: Rx: REGISTERED location: "/rd/yUo48kLNRY" Lifetime: 300s
Change (or register a change) of a value in a local object. This can be used to update values that are being ‘observed’ by servers.
Example, reporting a change without value (here we trigger a notification to observers of the ‘time’ resource):
> lwchange /3/0/13
Rx: report change!
Example, changing a value and reporting it to watchers (here we update the battery percentage to 90%):
> lwchange /3/0/9 90
Rx: value changed!
Trigger a server registration update for the given server now.
Example:
> lwupdate 123
List the available object instance URIs.
Example:
> lwls
/0/0 /0/1
/1/0
/2/0
/3/0
/4/0
/5/0
/6/0
/7/0
/31024/10 /31024/11 /31024/12
Remove the test object at /31024 (used to demonstrate dynamic objects)
Re-add the test object at /31024 after removing it.
Display objects (pulled from wakaama demo, not fully functional).
Example:
> lwdisp
Rx: /0: Security object, instances:
Rx: /0/0: instanceId: 0, uri: coaps://127.0.0.1:5784, isBootstrap: true, shortId: 111, clientHoldOffTime: 1
Rx: /0/1: instanceId: 1, uri: coaps://[fdaa:bbcc:ddee:0:a196:ec9a:66bc:f69]:5684, isBootstrap: false, shortId: 123, clientHoldOf
Rx: fTime: 1
Rx: /1: Server object, instances:
Rx: /1/0: instanceId: 0, shortServerId: 123, lifetime: 300, storing: true, binding: U
Rx: /3: Device object:
Rx: time: 1612527196, time_offset: +01:00
Rx: /5: Firmware object:
Rx: state: 1, result: 0
Rx: /6: Location object:
Rx: latitude: , longitude: , altitude: , radius: , timestamp: 1612517584, speed:
Rx: /31024: Test object, instances:
Rx: /31024/10: shortId: 10, test: 20
Rx: /31024/11: shortId: 11, test: 21
Rx: /31024/12: shortId: 12, test: 22
Display the security and server objects that are backed up during bootstrapping, in case of failure.
Example:
>lwdispb
Rx: /0: Security object, instances:
Rx: /0/0: instanceId: 0, uri: coaps://fdaa:bbcc:ddee:0:a196:ec9a:66bc:f69:5784, isBootstrap: true, shortId: 123, clientHoldOffTi
Rx: me: 10
Rx: /1: Server object, instances:
Rx: /1/0: instanceId: 0, shortServerId: 123, lifetime: 300, storing: false, binding: U
>
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