Presence API

The Presence API lets Gateway firmware inspect module availability and react when paired modules become unavailable.

For the conceptual overview, see Module Presence.

setModuleTimeoutHook

Registers a callback that runs when a paired module exceeds the configured timeout.

ArmorLink.setModuleTimeoutHook(
    [](const ArmorLinkStoredPairedModule& module, uint32_t silentMs) {
        ArmorLink.warn(String(module.name) + " went offline");
    });

Parameter	Description
module	Stored paired module metadata.
silentMs	Milliseconds since the last observed traffic.

isModuleOnline

Checks whether a module is currently considered online.

if (ArmorLink.isModuleOnline("E4:B3:23:C4:74:3C")) {
    ArmorLink.info("Helmet online");
}

Returns true for known modules that are currently online, otherwise false.

Gateway Events

Presence is also exposed to BLE/App clients:

• module_presence_snapshot
• module_presence
• module_unpaired
• module_pairing_required

These events are generated by the Gateway and are intended for UI synchronization.

Summary

Use the Presence API for Gateway-side decisions. Use the App-facing events to keep user interfaces aligned with the Gateway's paired-module list.