In the past few weeks, I’ve been actively looking at how I can manage all my ‘smart’ (or ZigBee/WiFi connected) IoT devices in my home from a central place.
I started with Home Assistant, but quickly found the user interface a bit too clunky for my appetite. Searching around, openHAB came up as a good contender and it meets almost all of my wants – active development, an APT repository, the ability to run under Docker and well-used by many people.
The thinking behind openHAB’s data structure confused me at first – a combination of things, channels and items didn’t seem logical to me until I got stuck in. It turns out it’s quite clever:
- A thing is a physical device, such as a smart plug or bulb
- Each thing has one or more channels, which are individually accessible data points on the device, such as an on/off switch (input), or energy usage monitor (output)
- Links connect a channel to an item, such as energy usage to a metric (output) or on/off toggle (input). Channels can have multiple links too
Where a thing is accessed via another device, such as a Hue bulb, a special type of thing called a bridge needs to be defined. The bridge discovers other things connected to it and publishes them ready for configuration. Bridges are instances of a binding, so if you have three Hue controllers, you have three bridges defined.
Lighting things up
Connecting my Hue lights was trivial. The Hue binding is included in the openHAB distribution, and is installed by clicking ‘Install’. Adding the bridge requires the IP address of the Hue bridge and a username, and a quick press of the hardware button on the bridge to pair things together. At this point, the bridge reports the devices connected to it, and it’s just a case of adding them as things.
Despite the UI feeling a bit fiddly to edit – similar to writing HTML in Notepad but having to indent it as it’s YAML – I absolutely love openHAB. In the coming weeks, I’ll write up how I connected my Glow IHD and CAB, a Tasmota switch for my porch light, my Ring doorbell and the problems I had with my TP-Link Tapo devices and how easy it was to fix them.