I am writing this after several months of discovery. Home Automation is a hot topic right now and there are so many different ways to approach it. On the one side there’s the expensive proprietary route where you’d be paying $50 just for a single smart switch after $100+ for the controller. This is, of course, the easiest way to do it. Then there’s the DIY method, which is much cheaper, but there’s only so far you can go down this path. Building your own thermostat or smoke detector, for example, would be a bit tricky.
So I chose a mixed approach, going as far as I could building my own sensors then adding pre-built ones where necessary. I really hope that this guide helps you, and saves you time going down the same rabbit holes and dead-ends that I did to find a system that works. It’s not intended as an instructional as those instructions are already out there, just a road map to a working system that doesn’t break the bank.


Home Automation, beware! you start with one sensor, then a switch, and before you know it it’s taking over your house… oh, that’s the idea. This could be a multi-year project but it’s great fun as you don’t have to wait until the end to benefit from the results. Nearly every week I’m adding something new and cool.

It all started after seeing some demonstrations of this company or other devices, drooling, then checking the prices. After I got up off the floor I thought there has to be a cheaper way. It is now 5 months and a lot of Googling (that’s a word now, right?) later. And my conclusion is that, if you are a hands on person, and can handle a soldering iron, there is a cheaper way for some of it but there is a line where one has to start laying out some dollars. The good thing is that being a longterm project the costs can be spread out over time.

Thanks to the great folk over at mysensors.com I got a good start on automating my home for very little cost. I ordered about 20 different parts from China that took from 10 to 30 days to arrive. It was exciting to open up all the packets to see what that day had delivered.

I built a serial gateway which plugs in via USB to a Raspberry Pi, downloaded and installed Domoticz Home Automation software. There are several options out there but this is the one I chose and I haven’t regretted it. It takes a little work to figure it out but once you get the hang of it there is a lot it can do, and there’s a great community.
Once the gateway was up and running I started with a simple door sensor, following the plans laid out on mysensors.com. I used a magnetic contact switch which I set into the back doors’ frame. After that it was fairly simple to repeat the process for all the doors and windows. It was great to see the floorplan on Domoticz filling up with sensors which change whenever a door or window opened.

I also put together a temperature sensor, a light sensor and a relay which I tied together into an Event in Domoticz. Events are created by using Blockly, a simple scripting language with jigsaw puzzle type pieces you fit together. So now, when the garage service door opens lights above the stairs to the house come on IF the lights in the garage are not on. Cool eh?

I also added a speaker to the Raspberry Pi and created some sound files. Now when the service door opens there a sound of Star Trek doors and a voice announces, “Garage Door Open”.

Up until this point each sensor had only cost me about $5. The serial gateway maybe a couple more dollars, and a Raspberry Pi which costs around $40. And, of course, my time but I enjoy doing projects like this.

Next I expanded what my controller could do by adding a simple 433mhz transmitter and receiver. With a lot more Googling I found that I could ‘sniff’ certain remotes’ codes and use Domoticz to repeat those codes to control those devices. I bought a set of 5 Etekcity Smart switches, and a set of 3 light adaptors that you can plug into a light between the bulb and socket. Both of which I could now control through Domoticz.

Another piece of the puzzle is to have Domoticz detect when your cell phone is in range of the house, handy for turning on outside lights on your arrival. Or, setting the alarm and turning off the lights when you leave. Links for all this are below.

So thus far everything was working fine and I hadn’t really spent that much money. But now that’s about to change. In-wall light switches are the problem. I did a lot of searching, tried various things to find a way to do this cheaply but without success. To cut a long story short I’ve had to go with a proprietary system. Maybe it is for the best as messing around with home-made electronics in the wall connected to the mains electricity could end very badly.

One thing I didn’t want was have another controller which didn’t talk to what I had already installed. I may want a light to go on if a door is open, so it all has to work together. Fortunately, those great folk at Domoticz have build in software to host various systems. I chose z-wave, and purchased an Aeotec z-wave USB stick which was really easy to install on the Raspberry Pi and include in Domoticz. So now I have a serial gateway, 433mhz controller and z-wave all in the same box plugged into the Raspi and brought together by Domoticz.

With the z-wave controller installed I have started buying GE z-wave switches to replace the generic manual light switches in the house. Although, the most expensive part of the project so far I believe it offers the best price per performance. And the Aeotec USB stick is really a cheap way to get z-wave into the system.

Having z-wave opens up the way, in the future, to be able to add smoke detectors and thermostat controls later on.

Links

One more thing to mention is that Domoticz has a mobile app for Android and iOS so everything can be controlled from your phone.

Tips
Re the 433mhz parts, I have found that the receiver works better if I only connect it when needed and shut down Domoticz when I want to sniff codes. Once I have the codes then I simply unplug the 5v line and restart Domoticz.