Apple’s Home Kit protocol

HomeKit. HomeKit is a framework for communicating with and controlling connected accessories in a user’s home.

HomeKit allows seamless integration between iOS devices and home automation accessories, by promoting a common protocol and providing a public API.

With HomeKit, Apple’s machinations go significantly further, aiming to turn your iPhone or iPad into an engine that drives potentially countless smart accessories about your home.

HomeKit allows seamless integration between iOS devices and home automation accessories, by promoting a common protocol and providing a public API for configuring and communicating with accessories. HomeKit enables a single app to coordinate and control a range of accessories from multiple vendors. Multiple accessories can act as a single coherent whole, without requiring vendors to coordinate directly with each other.

Working with Home Accessories

HomeKit allows third-party apps to perform three major functions:

  1. Discover accessories and add them to a persistent, cross-device home configuration database.
  2. Display, edit, and act upon the data in the home configuration database.
  3. Communicate with configured accessories and services to get them to perform actions, such as turning on the lights in the living room.

The home configuration database is not only available to third-party apps, it’s also available to Siri. This allows users to give commands like “Siri, turn on the lights in the living room.” If a user creates a home configuration with logical groupings of accessories, services, and commands, Siri can make it very easy to accomplish sophisticated operations with voice control.

Image result for Apple’s slowly emerging Home Kit protocol

Home Configuration

HomeKit views a home as a collection of home automation accessories. The purpose of having a home configuration is to allow the end user to provide meaningful labels and groupings to the home automation accessories they have purchased and installed. Apps can provide suggestions to help the user create useful labels and groupings, but should not impose their own preferences on the users—the user’s wishes are most important.

The basic data containment hierarchy looks like this:

  • Homes (HMHome) are the top level container, and represent a structure that a user would generally consider to be a single home. Users might have multiple homes that are far apart, such as a primary home and a vacation home. Or they might have two homes that are close together, but that they consider different homes—for example, a main home and a guest cottage on the same property.
  • Rooms (HMRoom) are optional parts of homes, and represent individual rooms in the home. Rooms don’t have any physical characteristics—size, location, etc. They’re simply names that are meaningful to the user, such as “living room” or “kitchen”. Meaningful room names enable commands like, “Siri, turn on the kitchen lights.”
  • Accessories (HMAccessory) are installed into homes and assigned to rooms. These are the actual physical home automation devices, such as a garage door opener. If the user doesn’t configure any rooms, HomeKit assigns accessories to a special default room for the home.
  • Services (HMService) are the actual services provided by an accessory. Accessories have both user-controllable services, like a light, and services that are for their own use, like a firmware update service. HomeKit is most concerned with user-controllable services.

    A single accessory may have more than one user-controllable service. For example, most garage door openers have a service for opening and closing the door, and another service for the light on the garage door opener.

  • Zones (HMZone) are optional groupings of rooms in a home; for example, “upstairs” and “downstairs” would be represented by zones. Zones are completely optional—rooms don’t need to be in a zone. By adding rooms to a zone, the user is able to give commands to Siri such as, “Siri, turn on all of the lights downstairs.”

Credit : Apple