For several years now, I’ve been experimenting with the integration of tech into the houses and apartments I’ve lived in. For the most part, this has manifested as very basic automation – some trivial routines in Phillips Hue, or an auto-off timer on a Wemo power socket, for example.
Well, in the past few months, I’ve been able to dramatically amplify my efforts in this realm by introducing a wide variety of Zigbee and Zwave home automation devices.
Zigbee & Zwave
The distinction between “secure” and “insecure” tends to follow the categorization of the device – you probably don’t want your wireless door lock to be accessible to anyone nearby that can transmit a Zigbee control code, but perhaps you don’t have quite the same concerns with a temperature sensor.
Both systems require a hub somewhere that owns the network and keeps track of the devices within. The websites of each protocol have information about possible hubs, but I went with a USB variant and connected it to HomeAssistant.
HomeAssistant is the “brains” of my home automation. Some folks use OpenHab as an alternative. I run my instance on a VMware server in my garage – you can run yours on anything from a home PC to a Raspberry Pi.
HomeAssistant is the hub through which all of the Zigbee and Zwave devices are communicating, sending their sensor readings and receiving commands. While it can also be used as a dashboard, I personally use a Grafana instance (also on my VMware server) along with InfluxDB and Prometheus instances to collect and present data from around the house.
HomeAssistant also allows automations that can use readings from various devices to make decisions and trigger other devices. For example, I have lights in my backyard that are turned on when the outdoor luminance drops to a certain level (rather than using sunset data), and turn off at 10pm unless there’s motion in the yard. This is just one example of what is possible – I’ve barely even begun to scratch the service in my own usage of HomeAssistant!
I’ve spent some time building up a Grafana dashboard that I can use as a quick go-to to see what’s happening in my smart home. Internet stats, power and water usage, and environmental data is all available at a glance.
My favorite part of this dashboard is the power data. Using a Smart Utility Meter connected to our PG&E meter, I was able to set up a data feed with point-in-time power meter readings. I had to write a little Python daemon to receive the regularly-submitted reports from the meter and push them to my InfluxDB instance, but once this was up and running, it’s been pretty solid! … other than one little bug with units that sometimes reported a power consumption of 1 MW or more – but once that got squashed, everything’s looked very reasonable.
My second favorite part of this dashboard!
Using a handful of Zwave multi-sensors, I have all sorts of useful data from various locations in the house – temperature, humidity, luminance, motion. Some of these I am already using in automation – the use of dwindling luminance to trigger turning on smart bulbs is very useful – but others are more informational.
I don’t yet use the other data for anything other than my own interest. It is however useful to know what the temperature is around the house, and I can use that to experiment.
Which brings me to…
All this data is useful to satisfy a curiosity, but I’ve been slowly starting to find new ways to make use of it.
Temperature data is useful to figure out if I should wear a jacket today (I should set up a push notification for that…), but I’ve also been experimenting with turning heaters on and off and seeing the impact on the longer-term temperature graphs. This is particularly interesting when looking at ways to trim back cost – heating isn’t particularly efficient, and if it is not making a major difference, that’s a strong signal that we can change our usage of it!
I’ve also used power data to recognize particularly power-hungry light fixtures and identify them as candidates for a bulb conversion. That’s something that’s doable without all this fancy tech, but I love how quickly I can see results – with the dashboard open on my phone, after throwing a light switch, I can see results in seconds and move on to another fixture.
Many folks have used these sensors for even more interesting purposes – calibrating the UV sensors to open and close blinds to protect furniture from UV rays, for example.
I’m barely scratching the surface of what’s possible, but it’s nonetheless an exciting place to be.
Just moments ago while writing this article, I realized it had become quite dark in my office. I think it’s time to publish this… and start working on an automation to turn the lights on when it gets dark and I’m working!