Z-Wave

Alexa as Home Automation Integration Point

Over the past few months I’ve done a lot of experimenting with getting various home automation technologies to communicate with each other. For example, setup a Raspberry Pi to bridge between SmartThings and Home Assistant using MQTT. SmartThings in turned connected to my Harmony Hub. Then tied in my Patriot custom electronics devices via MQTT. What I ended up with worked, but seemed overly complex. I don’t even want to try to blog about how to reconstruct such a beast.

So that got me thinking about how to simplify things. I realized that the individual pieces are are fairly simple: SmartThings, Patriot, Harmony. Each of these provides their own Alexa smart home skill, and most of what I want to accomplish can be done entirely by Alexa. So it isn’t really necessary to try to bridge between each of those. Instead, I can let Alexa be the common interface to each of them.

So that’s what I’m trying now. I’ve removed the bridging pieces, and will be using Alexa to control everything. Things certainly are simpler now. I’m hoping that the recently announced support for Echo Buttons indicates a direction for Amazon that will allow other inputs to be used with Alexa. Amazon is holding to their “voice first” mantra, but we’ll see where this goes.

In the meantime, I’m investigating whether I can trigger an Alexa skill lambda handler directly from a Patriot device. I think it may be possible…

Making Sense of Z Devices (Z-Wave vs Zigbee)

As I stated in my last post, trying to understand and control Z-Wave and Zigbee devices sure is confusing.

Having looked at several different controllers and hubs, and used both Zigbee and Z-Wave lights, I’ve come to understand the major differences. But it is indeed confusing.

So here is my simplified, high level understanding and comparison of these two:

  • Zigbee devices are cheaper than Z-Wave.
    • For example, the cheapest light bulbs today are about $9 for Zigbee, and $17 for Z-Wave. That’s no big deal if you only need one or two. It is a big deal if you’re replacing a whole house full.
  • Zigbee is natively supported by the new Echo Plus; no extra hub required.
    • But if like me you already have Alexa, Dots, and Shows, you’ll still need a hub.
  • Z-Wave devices are certified.
    • What this means is that they should inter-operate more reliably, but that is probably why they’re more expensive.

Confusion factors:

  • Zigbee and Z-Wave are not interchangeable.
    • You cannot control a Zigbee light with a Z-Wave controller, and vs. a vs.
    • The SmartThings hub supports both, but Echo Plus supports only Zigbee, etc.
  • Light bulb advertisements on Amazon don’t always say which one is supported.
    • I was searching for Z-Wave light bulbs, and kept getting Zigbee bulbs that do not say “Zigbee”. It would be very easy to purchase the wrong type.

So caveat emptor.