Module Presence

ArmorLink automatically tracks whether paired modules are currently online or offline.

Unlike many ESP-NOW frameworks, ArmorLink does not require dedicated heartbeat packets.

How Presence Detection Works

Whenever a module communicates with the Gateway, ArmorLink updates its internal "last seen" timestamp.

Module sends packet
        |
        v
Gateway updates Last Seen
        |
        v
Timeout exceeded?
    No -> Online
    Yes -> Offline

Any valid communication updates the module's presence information.

Examples:

ArmorLink uses activity-based presence detection.

This minimizes network traffic and reduces power consumption while still allowing reliable online/offline detection.

Presence behavior can be configured through ArmorLinkOptions.

ArmorLinkOptions options;

options.modulePresenceCheckIntervalMs = 300000;
options.moduleTimeoutMs = 900000;

Defines how often the Gateway checks module status.

Defines how long a module may remain silent before being considered offline.

A module is considered online if communication has been observed within the configured timeout window.

A module becomes offline automatically once the timeout expires.

Presence detection is performed by the Gateway.

Regular modules do not need to implement heartbeat logic or timeout tracking.

The ArmorLink App can display module availability information based on Gateway presence data.

This allows users to quickly identify disconnected modules.

ArmorLink provides automatic module presence detection.

Features include: