Non-standard
This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.
This API is available on Firefox OS for internal applications only.
Summary
The connected property indicates if the device is connected to the current device's adapter (true) or not (false).
Syntax
var connected = instanceOfBluetoothDevice.connected
Value
Return a boolean.
Specification
Not part of any specification yet. It should be discussed as part of the W3C's System Applications Working Group.