Monthly Archives: March 2016

Choosing a z-wave controller

In the last post, I looked at solutions for starting out my automated home and decided to go with z-wave as the primary protocol to start investing in. Now, we need to start with the central point, the primary controller which is going to act as the central hub for the network.

The first thing that I needed was a controller. There are quite a few options for this, including off-the-shelf options from companies like Fibaro and SmartThings as well as applications which can be installed on a home server. My initial concern was this is a fairly new market that isn’t very big yet and I didn’t know which of the companies were going to last and keep supporting the hardware that they had made. There was of course the cost aspect with the majority of off-the-shelf solutions costing over £100.

Like the SmartThings hub, both OpenHAB and Domoticz offer support for protocols other than zwave, including Phillips Hue, Nest, MQTT, IFTTT and Twitter. So they can integrate with other solutions that might be useful.

Being happy to manage a small Linux server, I decided that I wanted to run a software based controller rather than an off-the-shelf box as it could then be customised to do more if I want it to in the future. It also makes it potentially easier to switch software at a later date too. The key players in the home automation software space seem to be Domoticz and OpenHab. They both look decent and seem to have good support, though OpenHab offers an official iOS app while Domoticz seems to leave this to third parties. OpenHab also seems to have a very responsive forum with the developers quickly responding to people’s issues which settled it as the winner.

With the application chosen, I needed somewhere to run it. Although the household computer is usually running, “usually” isn’t going to cut it if it’s a critical part of the house’s lights and heating. The Raspberry Pi is cheap enough and has a desirably low energy footprint to be running constantly so it seemed the perfect choice. Out of the box though, the Raspberry Pi can’t control zwave devices as it lacks the necessary hardware. This is easy enough to solve, with several manufacturers making USB radios (that would also be compatible with any other machine with a USB port) and the Razberry daughterboard which is dedicated to the Pi. In choosing a hardware radio, definitely consult the documentation of the application chosen to make sure there are no compatibility issues though.

Together, the Pi and the Razberry came to nearly £100 – not much cheaper than the dedicated boxes – but the Pi can at least be re-purposed if it turns out not to be the best solution, and is flexible in that it can run other things too.