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Client Lifecycle

LWM2M client initialization, registration, and runtime management.

This module provides the top-level API for the wb-idf-lwm2m component. It manages the full client lifecycle:

Type Definitions​

wb_lwm2m_client_handle_t​

typedef struct wb_lwm2m_client* wb_lwm2m_client_handle_t

Opaque client handle.

wb_lwm2m_event_handler_t​

typedef void(* wb_lwm2m_event_handler_t) (wb_lwm2m_event_t *event, void *user_ctx)

User event handler callback.

Enumerations​

wb_lwm2m_event_type_t​

LWM2M event type enumeration.

EnumeratorValueDescription
WB_LWM2M_EVENT_CONNECTEDCoAP session established.
WB_LWM2M_EVENT_DISCONNECTEDCoAP session lost.
WB_LWM2M_EVENT_REGISTEREDRegistration successful.
WB_LWM2M_EVENT_REG_FAILEDRegistration failed.
WB_LWM2M_EVENT_REG_UPDATEDRegistration update successful.
WB_LWM2M_EVENT_DEREGISTEREDDeregistration successful.
WB_LWM2M_EVENT_BOOTSTRAP_DONEBootstrap completed (future use)
WB_LWM2M_EVENT_ERRORGeneric error.

wb_lwm2m_state_t​

LWM2M client state enumeration.

EnumeratorValueDescription
WB_LWM2M_STATE_IDLE
WB_LWM2M_STATE_CONNECTING
WB_LWM2M_STATE_REGISTERING
WB_LWM2M_STATE_REGISTERED
WB_LWM2M_STATE_UPDATING
WB_LWM2M_STATE_DEREGISTERING
WB_LWM2M_STATE_ERROR

Functions​

wb_lwm2m_add_object​

Register an LWM2M object with the client.

esp_err_t wb_lwm2m_add_object(wb_lwm2m_client_handle_t client, const wb_lwm2m_object_def_t *obj)

Parameters:

  • client (wb_lwm2m_client_handle_t): Client handle
  • obj (const wb_lwm2m_object_def_t *): Object definition

Returns:

ESP_OK on success

Must be called BEFORE wb_lwm2m_start() . The object definition is referenced (not copied), so it must remain valid.

wb_lwm2m_destroy​

Destroy the LWM2M client and free all resources.

esp_err_t wb_lwm2m_destroy(wb_lwm2m_client_handle_t client)

Parameters:

  • client (wb_lwm2m_client_handle_t): Client handle

Returns:

ESP_OK on success

wb_lwm2m_get_state​

Get the current LWM2M client state.

wb_lwm2m_state_t wb_lwm2m_get_state(wb_lwm2m_client_handle_t client)

Parameters:

  • client (wb_lwm2m_client_handle_t): Client handle

Returns:

Current state

wb_lwm2m_init​

Create an LWM2M client instance.

wb_lwm2m_client_handle_t wb_lwm2m_init(const wb_lwm2m_client_config_t *config)

Parameters:

  • config (const wb_lwm2m_client_config_t *): Client configuration

Returns:

Client handle, or NULL on failure

Allocates resources and creates the underlying CoAP client. Does NOT connect or register yet — call wb_lwm2m_start() for that.

wb_lwm2m_is_registered​

Check if the client is currently registered.

bool wb_lwm2m_is_registered(wb_lwm2m_client_handle_t client)

Parameters:

  • client (wb_lwm2m_client_handle_t): Client handle

Returns:

true if registered

wb_lwm2m_notify​

Notify the server about a changed resource value.

esp_err_t wb_lwm2m_notify(wb_lwm2m_client_handle_t client, uint16_t obj_id, uint16_t inst_id, uint16_t res_id)

Parameters:

  • client (wb_lwm2m_client_handle_t): Client handle
  • obj_id (uint16_t): Object ID
  • inst_id (uint16_t): Instance ID
  • res_id (uint16_t): Resource ID

Returns:

ESP_OK if the notification was queued

Sends a CoAP POST with the resource value in SenML-JSON format. Can be used to proactively push telemetry data.

wb_lwm2m_start​

Start the LWM2M client.

esp_err_t wb_lwm2m_start(wb_lwm2m_client_handle_t client)

Parameters:

  • client (wb_lwm2m_client_handle_t): Client handle

Returns:

ESP_OK on success

Connects the CoAP client and sends the LWM2M Registration request. Registration updates are sent automatically based on the configured lifetime.

wb_lwm2m_stop​

Deregister and stop the LWM2M client.

esp_err_t wb_lwm2m_stop(wb_lwm2m_client_handle_t client)

Parameters:

  • client (wb_lwm2m_client_handle_t): Client handle

Returns:

ESP_OK on success

Sends a Deregistration request and tears down the CoAP session.

wb_lwm2m_update_registration​

Send a registration update.

esp_err_t wb_lwm2m_update_registration(wb_lwm2m_client_handle_t client)

Parameters:

  • client (wb_lwm2m_client_handle_t): Client handle

Returns:

ESP_OK on success

Typically called automatically, but can be triggered manually (e.g., after object list changes).