Background: I have a linux tower PC in my office that also has a Mysa smart thermostat in it, and I wanted Home Assistant to know when I’m actively using that computer so it can know I’m in the room and adjust the room temperature automatically.
To make that work I wrote a Python script I can run from my user account on the workstation that subscribes to the screensaver DBus interface and updates an MQTT topic regarding my activity status. GitHub - bedaro/idle-tracker: MQTT Linux Desktop Idle Status Publisher So status is published to /<host>/user/<username>/status and takes either the value “active” or “inactive”
If anyone is interested in publishing other Linux system information to MQTT, I wrote the code in a way that’s meant to be flexible so it can relatively easily be adapted to other data.
Then in my HA configuration.yaml I can define a binary sensor linked to the MQTT topic:
mqtt:
binary_sensor:
- state_topic: <host>/user/<username>/status
name: Ben using workstation
icon: mdi:account
unique_id: ben_using_workstation
payload_on: active
payload_off: inactive
expire_after: 600
…and now Home Assistant knows about it! The rest is all in a (complicated) Node-RED flow.