Daikin AC automation with Nest Thermostat in EU

Hi there,

I’m new since a few days using Home Assistant.
Installation went okay, and I could easily discover and configure a few of my connected stuff, like Daikin AC. Nest Thermostat was not that simple as I own it since just after they closed the Nest developper account option, and before Google one.

So I satisfied myself by using Badnest which was again not that easy, because the removal of the orignal GitHub project page which forced me to go ahead and give some try with some remaining forks https://github.com/moreli/badnestha
Well road is never a straight line but at the end it’s working and I can have both in my Home Assistant dashboard which is already a good start.
It shows the values from the temp sensors, and changes them when I want to do so.

Now the crazy stuff I’m not able to handle is I’d like to “sync” Daikin AC with the temp value set from Nest Thermostat.
I had a look at the various script / services / automation capabilities, and as a real newbie here I’m far away from just understanding where to start and what to use.
I tried, especially using the “Development tools” menu, and whether I could use the “services” tabs to set static values to my AC, and the “Models” tab to read dynamic values from my Thermostat, I’ve been unsuccessful to achieve what I’m looking for…
Any idea ?

Let me reply to myself as I found some ways to do this, and it may help others…

I had no luck because Automations, which I was looking at first was partially failing, and actually only working using scripts.
The tricky part was to be able to set the Dakin A/C temperature in while reading its value from the Nest thermostat. To achieve this, you have to call service climate.set_temperature on your Daikin A/C entity climate.daikin1, and then you need to specify the right service data referring to your Nest thermostat temperature value:
temperature: '{{ state_attr(''climate.Nest_thermostat'', ''temperature'')|float }}'
For any reason I don’t know, you can’t directly use this last way of specifying the temperature directly into an Automation, but it works when in a script.

So I used the following script

  alias: Update Daikin 1
  - service: climate.set_temperature
      temperature: '{{ state_attr(''climate.Nest_thermostat'', ''temperature'')|float
    entity_id: climate.daikin1
  mode: single

and the following Automation

- id: '1603294244871'
  alias: Start and Sync Daikin via Nest
  description: ''
  - platform: state
    entity_id: climate.Nest_thermostat
    attribute: temperature
  condition: []
  - service: script.turn_on
    data: {}
    entity_id: script.update_Daikin
  mode: single

And then, it works… ! :smiley:
I wrote a couple of other automations to stop and also to sync from Daikin to Nest as well.
I will post them later on

Just updated my previous message to add |float argument as it was required to make this whole thing working without error