LwM2M Composite Observe

[e-va]

Hi,

I'm working on an LwM2M client that reads three sensors in sequence every N minutes and notifies the server about the value change.

The server supports the LwM2M 1.1 observe composite feature. It is based on leshan-server-cf 2.0.0-M5.

When the nRF9160 client sends three consecutive observe notifications they are not received as composite observe response on the server side. When each sensor value is observed on its own, the server does receive the single sensor value observe notifications.

My current client firmware is based on nrfconnect SDK version 1.6.1.

I've searched the github nrfconnect-sdk and zephyr repositories for any new notify functions but was unable to find anything aside from the following lines:

#define NOTIFY_OBSERVER(o, i, r) lwm2m_notify_observer(o, i, r)

#define NOTIFY_OBSERVER_PATH(path) lwm2m_notify_observer_path(path)

....

int lwm2m_notify_observer(uint16_t obj_id, uint16_t obj_inst_id, uint16_t res_id);

int lwm2m_notify_observer_path(struct lwm2m_obj_path *path);

My question is now: is the composite observe feature supported in any version of the nRF Connect SDK?

Thanks in advance.

Best regards

[Øyvind]

Hello, 

Do you have any log outputs from the device itself? Are there any errors in this log?

Please note that due to Christmas holiday our team is lighter staffed than normal, and response time is longer than normal. 

Kind regards,
Øyvind

[e-va]

Hi,

thanks for the hint with the fetch.

I did ask about composite observe in the zephyr users mailing list and found out that composite observe is not supported in the current zephyr version (2.7) but it will be in the future. (https://lists.zephyrproject.org/g/users/message/2850?p=%2C%2C%2C20%2C0%2C0%2C0%3A%3Arecentpostdate%2Fsticky%2C%2Cobserve%2C20%2C2%2C0%2C88259935)

BR

PS: for anyone who requires workaround which does not need to be perfectly clean - I've implemented the Report resource of the Virtual Observe Notify LwM2M object. I skipped the ObserveLinks resource since Corelnk format is not supported yet.