Building an Automated Home with Z-Wave in 2014
Ah, home automation – what an overworked subject. It’s been hot (or not) for 20 years.
Truth is, home automation needs to be shelved as a meaningless buzzword that encompasses way too many ideas.
As we just bought a new home, I was faced with the challenge of dealing with rewiring it so it matches today’s electrical standards (which is a very versatile concept). Fact is, wiring a home is a nightmare. You need to figure out early on which switch connects to which plug and then embed it deeply into your stone wall (in France). As a consequence it’s VERY expensive (around 100-150€ per switch) and totally inflexible.
My initial approach was to remove all the switches from the wall and just use phones and remotes – but Stephanie vetoed that idea, and let’s face it, switches are a needed convenience.
I spent a huge amount of time researching technologies to support the objectives: no wires, flexibility. To those objectives I had to add security and redundancy since I could not allow a downtime of weeks should the home go down and should I need to repair it. Yes – the concept of a home going down is a bit scary.
The first technology I really liked was Chacon’s DI-O. Direct communication between switches and plugs, and no central point of failure in the architecture. The only massive drawback: about a two second lag between the flip of the switch until the light toggles.
After an in-depth market study I landed on Z-wave as the most promising technology. Plenty of vendors (although you need to watch out for the Z-wave frequency – typically EU devices are incompatible with US devices), and plenty of devices. They don’t have modules as nice as Chacon’s for the wall switches, but since Stephanie didn’t want tech-looking switches I ended up hacking a KFOB2 to connect it to simple brass push-buttons that were ready to install.
On the power side, Fibaro micro-modules are pretty awesome: small and sleek and they do an amazing job. They also support cool sensors such as pH, K and more for saltwater aquariums (another side request for the new home :D).
As for the logics, since Z-wave requires a central controller I spent a lot of time prototyping solutions. The best consumer solution in my opinion is Smartthings: cheap, efficient, beautiful, but unavailable in EU (remember the incompatibility between the EU and US Z-wave thing?) Another weird thing is that it’s currently network-dependent. Alex, the CEO of Smartthings, says they’re going to make it offline-ready but in the meantime it’s scary to think that a net outage would break your home (let’s face it, in the consumer Internet, outages are a reality).
Second best is Fibaro’s, but the only viable option that supports proper scripting is the Home Center 2 (lite has no lua capabilities), it also retails at 600€, which defeats the purpose of going with an ROI option. I was mostly concerned about potential hardware failures and how tough it would be to find another working box when this happens in 5 years.
I was feeling more comfortable with Raspberry Pi solutions, I could get a backup Pi for 50$ and keep it around in case of failures. After testing all the solutions I ended up liking Domoticz the most. While far from perfect, it has a very active community and fast paced iterations, which I’m confident will enable me to reach my goals. It also has a great web UI and a great Android app called Dromotica.
Next step: actually installing the whole thing in the house :). Bottom line: I’ll be saving around 60€ per switch with this solution and I’ll get way better flexibility (and a cool shutdown button by the door to turn off all the lights before I leave home).