Heartbeat
The Heartbeat feature provides the capability to monitor Bluetooth Mesh nodes and determine the distance between them.
The Heartbeat feature is configured via Configuration Server model.
Heartbeat Signal Messages
Heartbeat messages are transmitted as Transport Control Data Packets through the network, and are encrypted solely using a network key. These messages include the original Time-To-Live (TTL) value used for sending the message and a bit-field representing the active features on the node. In this way, the receiving node can determine how many relays the message had to pass through to reach the receiver, as well as which features the node supports.
Available Heartbeat feature flags:
Publishing Heartbeat Signals
Heartbeat publication is controlled via the Configuration model and can be triggered in two ways:
- Periodic Publishing
The node periodically publishes new Heartbeat messages. Publishing can be configured to stop after a certain number of messages or to continue indefinitely.
- Triggered Publishing
The node publishes a new Heartbeat message every time a feature changes. The set of features that can trigger a publication is configurable.
The two publication types can be combined.
Subscribing to Heartbeat Signals
Nodes can be configured to subscribe to Heartbeat messages from one node at a time. To receive a Heartbeat message, both the source and destination must match the configured subscription parameters.
Nodes can be configured to subscribe to Heartbeat messages from one node at a time. To receive the messages, both the source and destination must match the configured subscription parameters.
All Heartbeats received with the configured subscription parameters are passed
to the bt_mesh_hb_cb::recv event handler.
When the Heartbeat subscription period ends, the bt_mesh_hb_cb::sub_end callback will be invoked.
API Reference
- group bt_mesh_heartbeat
Heartbeat.
Defines
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BT_MESH_HB_CB_DEFINE(_name)
Register a callback structure for Heartbeat events.
Registers a callback structure that will be called whenever Heartbeat events occur
- Parameters:
_name – Name of callback structure.
Functions
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void bt_mesh_hb_pub_get(struct bt_mesh_hb_pub *get)
Get the current Heartbeat publication parameters.
- Parameters:
get – Heartbeat publication parameters return buffer.
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void bt_mesh_hb_sub_get(struct bt_mesh_hb_sub *get)
Get the current Heartbeat subscription parameters.
- Parameters:
get – Heartbeat subscription parameters return buffer.
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struct bt_mesh_hb_pub
Heartbeat Publication parameters
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struct bt_mesh_hb_sub
Heartbeat Subscription parameters.
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struct bt_mesh_hb_cb
Heartbeat callback structure
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BT_MESH_HB_CB_DEFINE(_name)