Home Assistant (HA) is the most capable open-source smart home platform for KNX integration. It bridges KNX group addresses to any non-KNX device — Sonos, Shelly, Velux, Nuki, Axis cameras — in a single automation layer. The Lovelace dashboard gives clients a free, customisable interface. The Companion mobile app provides secure remote access. This guide covers the complete setup from KNX connection to production-ready dashboard.

Hardware and installation

HA runs on many hardware platforms. For professional KNX projects requiring reliability: Intel NUC mini PC (NUC12WSKi5, 8GB RAM, 128GB SSD, fanless options available), with a UPS backup. The NUC runs HA OS (the full HA-managed Linux distribution) flashed to the SSD. Installation: download HA OS image from home-assistant.io, flash to USB drive with Balena Etcher, boot NUC from USB, HA installs to SSD in 10 minutes. On first boot, HA web interface available at http://homeassistant.local:8123.

Budget option for residential: Raspberry Pi 5 (4GB) on HA Yellow (official HAss.io hardware) or Home Assistant SkyConnect USB stick. Reliability note: Pi 5 with quality SD card is adequate for residential KNX projects — use a high-endurance A2-rated SD card and enable automatic HA backup to network share.

KNX integration: connecting to IP router

HA KNX integration connects to your KNX IP router or IP interface via KNXnet/IP. The HA server must be on the same LAN subnet as the KNX IP router (or connected via a routed subnet with multicast routing enabled). Configuration in HA UI: Settings → Integrations → Add Integration → KNX. Enter: Host = KNX IP router IP address, Port = 3671, Local IP (optional, for multi-NIC servers). Alternatively, add to configuration.yaml:

knx: tunneling: host: "192.168.1.50" port: 3671 local_ip: "192.168.1.100"

After connection: HA shows KNX Integration card in Integrations. The integration supports both tunneling (1 virtual connection to the router) and routing (multicast) modes.

Entity YAML: mapping KNX to HA

Define KNX entities in configuration.yaml (or via KNX panel in HA UI). Each entity type maps to a different HA domain:

Light entity (1-channel dimmer): platform: knx name: "Living Room Ceiling" address: "1/0/1" # switch on/off (DPT 1.001) brightness_address: "1/0/2" # 0-255 (DPT 5.001) brightness_state_address: "1/0/3" # feedback

Cover entity (shutter/blind): platform: knx name: "Living Room Shutter" move_long_address: "2/0/1" # up/down (DPT 1.008) position_address: "2/0/2" # position (DPT 5.001) position_state_address: "2/0/3" tilt_address: "2/0/4" # slat angle tilt_state_address: "2/0/5"

Climate entity (HVAC zone): platform: knx name: "Living Room Climate" temperature_address: "3/0/1" # actual temp (DPT 9.001) target_temperature_address: "3/0/2" # setpoint (DPT 9.001) operation_mode_address: "3/0/3" # mode (DPT 20.102)

Binary sensor (presence, alarm): platform: knx name: "Entrance Motion" state_address: "4/0/1" # 1=motion (DPT 1.001) device_class: motion

Lovelace dashboard: professional layout

HA Lovelace is the dashboard builder. For KNX projects, use these card types: Mushroom Light card (from HACS community store) — shows brightness slider and colour temperature picker for DT-8 DALI-2 lights linked via KNX. Mushroom Climate card — shows temperature, setpoint and mode for KNX climate entities. Mushroom Cover card — shows shutter position with up/down/stop buttons. History Graph card — plots KNX sensor values (temperature, CO2, energy) over configurable time ranges. Gauge card — live CO2 ppm, energy power, outdoor temperature from KNX sensor entities.

Dashboard layout: create separate views (tabs) for each floor or function: Ground Floor, First Floor, Energy, Cameras, Security. Each view uses Grid layout with cards organised by room. Example room card: Grid with Mushroom Cards for ceiling light, floor lamp, shutter, thermostat — labelled with room name as card title.

Mobile Companion app and remote access

HA Companion app (iOS/Android, free) connects to HA instance. Local discovery: app finds HA via mDNS on same WiFi. Remote access options: (1) Nabu Casa cloud subscription ($65/year) — encrypted relay, no VPN setup, mobile notifications included. (2) Self-hosted WireGuard VPN on home router (OpenWrt, Unifi, pfSense) — free, no ongoing cost, best privacy. (3) Cloudflare Tunnel (free) — HTTPS public endpoint proxied through Cloudflare CDN.

Push notifications: configure HA automation to send notification when KNX alarm binary sensor triggers. Example: KNX motion sensor at entrance → HA binary sensor → automation: "when state changes to on, send notification to mobile app with title 'Entrance motion detected', message '{{ now().strftime('%H:%M') }}'". Notification appears on lock screen with sound within 1-2 seconds of KNX telegram.

Voice control: HomeKit, Alexa, Google

HA HomeKit integration (built-in, no subscription): HA acts as a HomeKit bridge — all HA entities (including KNX-linked lights, covers, climate) appear in iOS Home app and respond to Siri. Pair via QR code in HA HomeKit integration settings. After pairing: "Hey Siri, dim the living room to 40%" works natively. Amazon Alexa: via Nabu Casa (Alexa skill) — HA lights appear in Alexa app. Google Assistant: via Nabu Casa Google integration. For local-only voice (no cloud): use Wyoming Protocol local voice processing on HA + Home Assistant Voice PE (official hardware) — completely local, no cloud dependency.

Energy monitoring and InfluxDB history

HA Energy Dashboard: built-in view that aggregates KNX energy sensor entities (kWh) into daily/weekly/monthly charts. Configure: Settings → Energy → Electricity Grid → add KNX energy sensor entity (DPT 14.019 kWh). HA stores entity history in SQLite (default) for 10 days. For longer retention (years) and Grafana visualisation: add InfluxDB 2.0 as HA long-term storage — all KNX sensor entity values are written to InfluxDB every state change. Grafana queries InfluxDB for dashboards: heat pump COP over 3 months, per-circuit energy consumption per day, CO2 levels by time-of-day. This historical analysis is impossible with standard KNX room controllers — it requires the time-series database that HA+InfluxDB provides.