Experience with Smart Lights

Since I moved to a new apartment in September, I also started to re-build my Home Automation system from scratch. At the old place, I didn't really have automated lights (except for some decorative LEDs and the sunset/sunrise-triggered terrarium lights). I never really had the urge to get the lights to turn on automatically based on presence.

But listening to the Home Assistant Podcast, everyone there seemed super excited about automated lights. So I decided to give it a shot.

I got a bunch of smart light bulbs as well as motion sensors from Ikea and Xiaomi and Wow! I didn't think I would like it that much, but I really do. My automations include turning on the lights next to the apartment entrance either when movement is detected, or when the door is opened. The area is quite dark, as it is far from any windows, so it is super convenient to have the lights turn on automatically. I have both a motion and a door sensor, because that way I can tell if someone is leaving or entering by checking which sensor triggers first. So far no automations are based on it, but I have some ideas for it.

A similar automation based on movement is the kitchen light. I really like it not having to press the light switch every time I walk in there. One issue with the kitchen is, that the lights also turn off when the sensor stops reporting movement. If someone is working in the kitchen and not walking around a lot, the sensor actually doesn't see that person and the light turns off. I don't have a really good solution so far. Currently, I simply deactivate the automation if it annoys me (a little button in the kitchen turns the automation off for an hour). A better solution might be to get a better presence sensor. I have heard good things about the Homematic IP presence sensor, which is supposed to detect even the smallest movements. However, it is also relatively expensive, especially compared to my cheap Xiaomi sensors.

Motion-triggered lights are also set up in the bedroom. And then there are automations based on sun position. When it starts to get dark in the evening, a number of low lights with warm colors turn on around the apartment, giving it a homey feeling. The lights also turn off after midnight.

I am currently in the process of implementing a night mode. The plan is to say good night to the Siri voice assistant and let that turn on night mode. In night mode, the lights will turn off, the motion detection in the bedroom will be deactivated, and other motion detection will only turn on dim lighting, so I don't get blinded when walking to the bathroom at night.

How it's implemented

I have lights from different vendors: most of the bulbs are Ikea TRÅDFRI lights, there is one Xiaomi bulb, two Phillips Hue lights and one Osram Smart LED stripe. I knew from the beginning that I probably wanted to integrate lights from several vendors and since all of them use the Zigbee communication protocol, they should theoretically be able to work well together.

And it turns out they do work together. As a Zigbee gateway, I use a Conbee USB stick that is plugged into the PC which is running home assistant. On the computer, I also run a deconz docker container. Deconz is a software for managing Zigbee networks. The container also includes Phoscon, which is an app to configure and control Zigbee devices. It is mostly aimed at light installations and also works with Zigbee sensors.

It took me a while to figure out how to pair each light with the Phoscon app, but I managed to get the lights of all vendors to work. Some lights must be turned on and off for a certain number of times to be put into pairing mode and many of them must be very close to the gateway for pairing, which is a bit annoying when one has a lot of lights.

The deconz/Phoscon container is automatically detected by the Home Assistant installation and all lights and sensors that have been paired are usable within Home Assistant. That is with the exception of switches. I do see entities that correspond to my Zigbee switches, but these only tell me the battery level in home assistant. Unfortunately, I cannot see the state of the switch or use a button press as an event to trigger an automation. Other than that the system is fairly good.

Noteworthy experiences 

There are still a few things that aren't perfect. First, I realized that smart lights that are turned off via their smart functionality (not by taking away their electricity) use a bit more energy than I anticipated. A typical Ikea bulb takes about 0.5W when it is turned off. That means that with a few lights, we quickly approach the energy consumption of a Raspberry Pi. This isn't super much, but it adds up. Especially when living in a country with high electricity prices. But lights from other vendors are far worse. My Xiaomi bulb uses 2W when it's turned off. I am glad I didn't buy more of those lights.

Unfortunately, some of the bulbs also emit an annoying high-pitched noise when they are turned off. That seems to be mostly the smaller bulbs by Ikea. Fortunately, I only have one floor lamp with these bulbs. And since that lamp includes six bulbs, I want to disconnect it from power when it's not in use, anyway. Currently I do it manually, but in the future, a smart power socket is planned to take over the job.

Finally, I realized that Zigbee is not as reliable as I thought. At least it does not have the range I expected; especially through walls. What I considered to be a minor obstacle, often causes sensors to drop out of the Zigbee network.

I had the expectation that the Zigbee mesh would help avoid such issues. But now I realize that the devices I have may not even be creating a mesh network, as many of them are battery powered. Deconz has the ability to show the connections in the Zigbee network, but it seems broken in my current installation, so I do not have a way to debug. I might try getting some Zigbee repeaters and place them around the apartment.

Well, those were my first experiences with smart lights. I really like the concept and want to gradually convert all lights in the apartment to smart lights. Because if some of them stay dumb, it feels really awkward. I sometimes forget that some lights do not work automatically and get really confused.