The modular structure of Home Assistant enables communication with other devices or services and expands Home Assistant with additional functions.

What is an integration in Home Assistant?

Home Assistant supports a large number of different manufacturers and integrates their devices or services via so-called integrations. The integrations ensure, among other things, that different devices can be made available uniformly in Home Assistant.
An example of an integration would be a Zigbee gateway: Home Assistant communicates with the gateway via the integration, whereby its devices - for example, connected lamps or sensors - can be made available uniformly in Home Assistant. Depending on the devices, communication does not necessarily have to take place via a gateway: Certain WLAN devices are usually addressed directly via an integration using the IP address (see: Shelly). In addition to providing devices, an integration can also be used to add certain services to Home Assistant, such as the Home Assistant Community Store, see HACS.

What are entities in Home Assistant?

Entities in Home Assistant reflect certain values, details, or properties of a device. For example, a temperature sensor may provide certain values as an entity:the temperature, humidity, air pressure, or battery status. Another example would be the properties of a lamp, this is likely to have as an entity a switch for turning it on and off and possibly another entity for adjusting the brightness or its light color.

ZigBee integration using the example of the Conbee2 - USB stick

To be able to use ZigBee devices with Home Assistant, I use the ConBee2 USB stick. Alternatively to the gateway solution of the manufacturer: Phoscon I recommend the use of ZigBee2MQTT or even better ZHA, see: HA: 3 different integrations for the ConBee 2 USB stick.

Home Assistant Community Store (HACS)

An example of an integration that provides a service is the connection to the Home Assistant Community Store (HACS). HACS is an integration to download GitHub repositories via a kind of software catalog.

I installed HACS via a command in the Docker container:

user@rechner:~$ docker exec -it home-assistant bash
bash-5.0# wget -q -O - https://install.hacs.xyz | bash -

Enabling the store is done via: Settings, Integration

and afterwards the installation has to be registered on GitHub, see: hacs.xyz/docs/configuration/basic

Once the store has been activated, additional custom components: Integrations or front-end packages can be added.

Adding a repository via the Home Assistant Community Store initially only causes the associated integration to be found via "Add Integration".

Integrations installed via a HACS repository are marked as "Custom Integration":

System Monitor

To monitor the operating system - on which Home Assistant runs - in a rudimentary way, additional sensors can be added in configuration.yaml, as an example Disk and Memory:

configuraton.yaml:

sensor:
  - platform: systemmonitor
    resources:
      - type: disk_use_percent
        arg: /
      - type: disk_use_percent
        arg: /daten
      - type: memory_free    

Monitor server or Linux systems

If you want to monitor the status of other Linux systems, you can use the integration "Glances". Glances collect data about CPU, memory or the free space of a hard disk and much more. As a prerequisite, Glances must first be installed on the systems to be monitored, see also: Glances - Monitor Linux Server

Shelly

An example of an integration that communicates directly with a WLAN device is the WLAN switch Shelly:

Since Home Assistant makes it easy to connect different systems, I use a WLAN switch in addition to ZigBee. Shelly is a small flush-mounted WLAN switch for controlling e.g. a power socket.

After setup, the device is automatically assigned to the default home dashboard:

Device Tracker OpenWrt

If you want to track the presence of devices via OpenWrt, you can do this with the device_tracker entry in the configuration.yaml file:

device_tracker:
  - platform: luci
    host: 192.168.1.2
    username: root
    password: ???
    interval_seconds: 30
    consider_home: 360
    new_device_defaults:
       track_new_devices: true

For OpenWRT the package luci-mod-rpc is required.

For information on OpenWrt, see: Alternative Router Firmware: OpenWrt and no longer DD-WRT

Alternatively, the status can also be queried via a ping:

Ping to a network device

If you want to track the presence of devices via OpenWrt using a ping, you can do this with the binary_sensor entry in the configuration.yaml file:

..
binary_sensor:
  - platform: ping
    name: FireTV
    scan_interval: 120
    host: 192.168.1.104
..

The status of the sensor is depending on the accessibility of the device: "off" or "on".

Connect MQTT devices as sensor

After adding the MQTT integration, a new sensor can be created in the configuration.yaml file:

MQTT requires an MQTT broker server, see MQTT - Broker : Docker Setup.

Adding individual sensors in the configuration.yaml file:

sensor:
  - platform: mqtt
    state_topic: "flowmeter/flow"   
    name: "flowmeter"
    unit_of_measurement: "m³/h"

Services that use the MQTT broker:

• Zigbee2MQTT, see : Commissioning Zigbee2MQTT in Docker - step by step
• "AI-on-the-edge-device" digitizer, see : Monitor water meter, record consumption: ESP32-Cam
• smart meter, see : Read out smart meter of the network operator KAIFA MA309M