Home Assistant [1] is an open source home automation system written in Python. The software supports a variety of open protocols and hardware components for home automation, including:

• Reading sensors
• Detecting the presence of people
• Requesting the weather or the position of the sun
• Controlling lighting
• Playing music through media players
• Regulating the thermostat

After a recent move to a new city, I decided to give Home Assistant a try. I wanted to equip my new apartment with Philips Hue lamps, Sonos wireless speakers, and various other sensors to support automation. My main criterion was that the technology remain invisible in my normal daily routine and that Home Assistant would, preferably, work entirely in the background.

Containerized

Home Assistant requires a Linux System. An ordinary Raspberry Pi, acting as a dust catcher under the sofa is fine. Home Assistant makes no particular demands on the memory and processing power. If you prefer to keep your home-grown projects farther apart, Proxmox VE (Figure 1) [2] or other virtualization platforms provide a useful service.

Figure 1: Many users prefer to run Home Assistant in a container environment.

To get started, create an additional user for the Home Assistant account and install additional packages on Ubuntu Server 16.04:

adduser --system homeassistant
apt-get install python-pippython3-dev
pip install --upgrade virtualenv

Next, install Home Assistant in a virtual environment in the home directory of the user account you just created (see Listing 1).

One advantage of locking up Python in a virtual environment is that, if necessary, Home Assistant can install more Python packages during operations, and the installation will occur in a separate directory tree – without the need for root privileges on the base system.

Once you complete the installation, you can check to see whether Home Assistant is working by calling it directly in the shell:

sudo -u homeassistant -H /home/homeassistant/ha/bin/hass

The project documentation [3] offers a detailed description of how to configure Home Assistant so that it automatically restarts after a reboot.

When first launched, Home Assistant sets up a sample configuration file in /home/homeassistant/.homeassistant/configuration.yaml. The config file lets you set values for the time zone and the location of your home automation setup. Home Assistant then installs some additional Python packages and listens for browser users on port 8123 and the local IP address.

Initial Installation in Your Very Own Home

Thanks to auto discovery, Home Assistant recognizes a variety of devices [4] without any configuration up front. To make things even easier, the program lets you set up the detected devices (Figure 2).

Figure 2: Home Assistant has discovered a Philips Hue base station and wants to configure it.

Component Glue

Almost all of the features of Home Assistant are implemented as components. If you cannot find the feature you need in the library of more than 600 components, you can still use Home Assistant to connect your hardware with one of the generic protocols (MQTT, HTTP, and others), as long as you are willing to do a little programming. I have written a small web service for my Geiger counter, which supplies its values via a serial interface; the service outputs the current radiation levels as a JSON document, which is then accessed by Home Assistant.