Can HomeKit mimic a virtual thermostat?

I don't yet have a homekit hub, so I can't fully test it. I have thermostats (Mysa) that are cloud or homekit-only. I'm wondering if I can basically create virtual thermostats in Hubitat, adjust those as needed... bring those into HomeKIt with the integration, and then have homekit automations or similar that basically watch for virtual thermostat changes and copy the set value to the physical thermostat? Is that possible?

Orrr is there a better approach?

Hubitat's HomeKit integration supports built-in virtual device drivers, and there is a built-in virtual thermostat driver. So it should be possible to add that to the Apple Home app through the Hubitat integration.

However, I'm not sure how easy it would be to use Apple Home app or Shortcut app automations to mirror any changes from a virtual thermostat to your Mysa thermostats. My guess is it would be possible, but tedious to implement (e.g. a separate automation for every possible change to each thermostat). And perhaps it's not possible for certain virtual thermostat setting changes to be used as triggers in the Apple Home or Shortcuts apps, it depends on what those apps allow as triggers.

2 Likes

Yes, the 2nd part is basically my exact question as I don’t actually have a HomeKit hub to be able to play around with and find out

I don’t do much automating on the iOS end of things (in case that wasn’t already obvious :slightly_smiling_face:).

But based on this guide from Apple, I’m thinking it’s unlikely you’ll have the triggers you need.

1 Like

I have Ecobee thermostats that work the same way (cloud or Homekit-only), and I don't have a Homekit hub (or any other Homekit devices). What I did to replace the cloud Ecobee integration is to use Home Assistant on a Raspberry Pi to act as a Homekit controller, and get local control of my Ecobees that way. I then used [RELEASE] Home Assistant Device Bridge (HADB) to bring that locally into my Hubitat hubs.

This gives me all the monitoring I want of the thermostat and some control (that I don't use).

So I managed to use my iPad as a home hub and indeed it seems there isn’t a nice clean way to mimic a thermostat.

I suppose I can just use a virtual switch or similar, given that at least from an automation standpoint I’m really mostly adjusting it for “home” and “away”. I suppose at least over time I could also adjust it based on a temperature sensor or outside temp to set higher or lower…

At least makes it MOSTLY functional and fully automated…

Is certainly annoying to sort of have to replicate/create these automations and rules outside of hubitat. Definitely no such thing as a “central hub” - yet - it seems! :frowning:

This is one reason why many of us designed our smart homes with devices that directly pair to Hubitat, permitting their automation from a central hub.

While I realize it isn’t always feasible to replace existing devices, should you do so in the future, Sinopé makes zigbee thermostats that control the same types of line-voltage devices as Mysa thermostats. And Stelpro makes line voltage zwave thermostats.

I do use Apple Home, but almost entirely as a “dashboard”.