Ruuvi
Reads RuuviTag BLE sensors - temperature, humidity, pressure, and battery voltage - broadcast directly over Bluetooth. Nothing to connect to: a RuuviTag broadcasts continuously and Athena just listens, decoding the public "Data Format 5" payload directly.
Adding a tag
No pairing wizard and no reachability check at add time - there's nothing to dial. Add by name and MAC address; the Add-tag screen also shows a live "Nearby tags" list of MACs currently broadcasting valid Ruuvi data that aren't registered yet, so you can just pick one. A tag shows as offline until its first broadcast is received, and "online" simply means a broadcast was seen within the last couple of minutes.
What's exposed
Temperature, humidity, pressure, battery voltage, and movement counter - all read-only. This is the only fully read-only integration in Athena: there's nothing to command, so it works with Dashboard cards and Automation triggers/conditions but has no actions.
Not currently wired into the History page's own multi-entity graphs (a Dashboard Chart card still works for a single entity's own history). This integration is also unverified against real hardware - the payload format is confirmed against Ruuvi's own published spec, but no live tag was available to test against during development.