Create a entity that report the seconds proxy is out skull

[DAVIZINH0]

Is your feature request related to a problem? Please describe.
Hello. Sometimes a proxy disconect or not reporting information. Tipically skull icon in bermuda.
This is a problem with a easy solution with a automation. Maybe reboot of esphome or reconect command in the wifi router.

Describe the solution you'd like
my proposal solution is a entity per each esphome with the seconds offline, or maybe a entity with on or off icon, or skull.
i dont know why but a entity per device that show the offline proxy in bermuda

thanks a lot for your work. this is a very interesting project!!!!

[agittins]

Great idea. I'll give this some thought as to how best to implement it. There have been some discussions already on having this value available as a diagnostic sensor in #363 so I might end up closing this as a duplicate, but I'll keep it open for now as this comes at it from a slightly different angle which might change how I see it.

To reduce sensor-churn and extra database writes, I'm thinking that showing the seconds since last update might be best (rather than a continually updating timestamp), and it should probably have a threshold or something before it kicks in, so we aren't continually writing 0 seconds, 1 second, 0 seconds etc. Maybe a windowed average, and call it "average update rate" 🤔 that way it will settle to whatever is typical for that given proxy, and a rising figure will be easy to catch in an automation.

[DAVIZINH0]

Your are right, the seconds Maybe its a problem to the recorder database.
But a parameter to set up the deadline in seconds like 30 seconds.
And a sensor with values "online" / "offline" .
When the Bluetooth proxy is 30 seconds offline, the this sensor have "offline" value. And when Bluetooth proxy is online or less thant 30 seconds online, this sensor have "online" value.
This value of 30 seconds can be configure each user, or not. I dont know if this timeout is diferent per users or the same for all of us.

This aproach not record a lot of information in recorder.