Read / Write lwm2m resource instance

Hi all,

I'm implementing a lwm2m client on a NRF9160 and have a problem with read/write resource instances. I use Leshan demo server to test the object and a came across a problem on ‘Remote SIM Provisioning’ object 504. When I read ‘504/0/11’ it reads all instances of this resource, but when I try to read a single instance of this resource, got an error. See images blow

Read resource insntances OK

Read single resource instace NOK.

This is my first problem, because after i need to write.

Can anybody help?

Parents

0 ICM_UC over 4 years ago

Hi Charlie,

The changes in order to read a specific resource instance are minor.

In the file 'lwm2m_engine.c' function 'lwm2m_read_handler'

Need to change 2 thing

first <> from this

for (i = 0; i < loop_max; i++) {
		if (res->res_instances[i].res_inst_id ==
		    RES_INSTANCE_NOT_CREATED) {
			continue;
		}

		if (res->res_inst_count > 1) {
			msg->path.res_inst_id =
				res->res_instances[i].res_inst_id;
		}

		/* setup initial data elements */
		data_ptr = res->res_instances[i].data_ptr;
		data_len = res->res_instances[i].data_len;

to this

for (i = 0; i < loop_max; i++) {
		if (res->res_instances[i].res_inst_id ==
		    RES_INSTANCE_NOT_CREATED) {
			continue;
		}

		if (res->res_inst_count > 1) {
            if ((msg->path.level > 3U) && 
                (res->res_instances[i].res_inst_id != msg->path.res_inst_id)) {
                continue;
            }
			msg->path.res_inst_id =
				res->res_instances[i].res_inst_id;
		}

		/* setup initial data elements */
		data_ptr = res->res_instances[i].data_ptr;
		data_len = res->res_instances[i].data_len;

second <> From this

    if (res->multi_res_inst) {
        engine_put_end_ri(&msg->out, &msg->path);
		msg->path.res_inst_id = res_inst_id_tmp;
	}

	return 0;
}

    if (res->multi_res_inst) {
        if (msg->path.level < 4U) {
          engine_put_end_ri(&msg->out, &msg->path);
        }
		msg->path.res_inst_id = res_inst_id_tmp;
	}

	return 0;
}

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