Sensor Health and Heartbeat Monitoring

Adding uptime, RSSI, heartbeat and sensor status checks to understand whether each observatory node is alive, stable and trustworthy.

Telemetry is useless if the node is not trustworthy

Once multiple ESP32 nodes started sending data, the next question became obvious: how do I know that a sensor is still alive and working correctly?

A dashboard showing the last value is not enough. The system needs to expose freshness, connectivity and node health.

Each node can publish basic operational information such as uptime, Wi-Fi RSSI, last heartbeat, firmware version and sensor availability.

This creates a distinction between a real environmental value and a stale value left behind by a disconnected device.

Monitoring turns the observatory from a collection of scripts into a maintainable system.

The same logic applies to larger technology projects: data quality depends on observability, diagnostics and clear failure states.