When creating scenes in Home Assistant, they can be added to Apple Home via the HomeKit Bridge integration. However, these scenes are transferred as buttons rather than actual scenes.
Philips Hue, for example, successfully transfers its scenes to Apple Home as proper scenes, demonstrating that this functionality is achievable. Home Assistant should have the ability to do the same for its own scenes.
Currently, HomeKit Bridge incorrectly represents Home Assistant scenes as toggle buttons instead of proper scenes. If the button behavior is intentional or preferred by some users, an option to choose how scenes are transferred (as buttons or proper scenes) would be ideal.
Additionally, the Eve app can manage and edit these scenes, further supporting the argument that they should be correctly classified as scenes in Apple Home.
I do not know HomeKit, but HA scenes are really flexible and can contain many different types of devices.
My guess is that HA is more flexible than HomeKit and HA scenes might therefore not always be compatible with HomeKit.
Philips Hue scene are probably fully compatible with HoneKit and can therefore be converted to HomeKit scenes.
Scenes in HA are essentially dumbed-down scripts. They can have the same end result but with fewer options, and don’t even have a state, so once you enable a scene you have no idea if it’s active or not. Contrast with Apple Home where you can create a scene and if all the accessories happen to match the scene target, its state shows “on”.
Basically while both systems use the term “scene” they each have a very different idea of what that word should mean.
Personally, I think HA needs to fix this underlying problem to make scenes stateful before they can be detected correctly by Apple. The author of stateful_scenes in HACS has done some great work along this track. If this FR fixes that, then you have my vote.
Edited to add: another sticking point is that, for full compatibility you likely need to ensure every entity the scene controls is exported by HomeKit Bridge. So either the Bridge should throw a warning/error if you forgot to export a scene’s accessory, or the Bridge should automatically include all the scene’s entities as if the scene was an include_entity_globs filter entry. I posted another FR to improve the way filters are defined.
I’m fairly sure that scenes, like automations, only exist on the iOS-side of HomeKit. In other words: they are created, and stored, locally, either on your iOS device or on your Home hub(s).
I can’t find any reference to scenes in the HomeKit Accessory Protocol specification, which would be a requirement for a bridge to be able to “send” a scene to your iDevices.
Stateful scenes would be nice, but it would require devices which report a state and HA have many integrations and devices that does not have this capability.
This is an excellent point — I didn’t notice at first that HMActionSet is not part of HAP, but it’s an iOS API that allows apps running on a phone or tablet to create and control HomeKit action sets (scenes). So if scenes can’t be part of the bridge, I wonder if — in theory — the HA companion app for iOS could offer an option to automatically create HomeKit scenes to mirror your HA scenes?
This statement confuses me… the underlying YAML for a scene definition appears to only list entities, so I must be missing where devices come into play?
In reading about this, I found a couple similar/duplicate FR topics. They indicate more confusion over this disconnect when HA stateless scenes export to HomeKit as stateful switches. One poster even suggests using groups instead. I’d offer that Scenes should exist, conceptually, in the middle ground between smarter groups and simplified scripts. Apple Home simply does a better job implementing this.
Theoretically, perhaps, but this sounds fairly complicated to me, given the differences between HA and HK scenes (the statelessness of HA scenes being a major one).