Need Help Creating Trigger For When Entity Has Not Changed Over A Time Period

Configuration
1

I’m trying to create an automation that runs when a Raspberry Pi is no longer on the network. I have a Raspberry Pi in my attic that tracks ADS-B air traffic, and from time to time it drops off the network, I am trying to create an automation that detects when this happens. I have the RPI Monitor running and the condition I want to create a trigger for is when the CPU hasn’t changed in XX minutes shown in the screenshot below

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When it drops off the network the CPU flatlines at it’s last reading, so I’m not really sure how to set that up.

A nudge in the right direction would be appreciated.

2

Check here for a starting point
Display recently triggered automations - Share your Projects! - Home Assistant Community (home-assistant.io)

3

Or you could ping it from HA. That woiuld give you a binary sensor that’s on or off to use as a trigger.

4

looks to me like you have an entity on it already that stops changing. so i think you want last_changed. if you have an automation that stops getting invoked you can use last_triggered as @jeffcrum posted. you can create a template automation that directly triggers off of last_changed being longer than your threshold.