Raspberry Pi Projects

Project 5 — Home Automation with Home Assistant

What is Home Assistant?

Home Assistant (HA) is an open-source home automation platform that runs entirely on your own hardware. It connects to thousands of smart home devices — lights, thermostats, sensors, cameras, door locks, voice assistants, and more — and lets you control them all from one interface, create automations ("when the sun sets, turn on the lounge lights"), and build dashboards tailored exactly to your home.

Unlike Amazon Alexa or Google Home, everything stays on your network. You own your data, your automations work without internet, and you are not at the mercy of a company shutting down its cloud service.

Home Assistant integrates with over 3,000 different devices and services — the largest ecosystem of any home automation platform.

Choosing an Installation Method

Home Assistant comes in four flavours. The differences matter — choose the wrong one and you'll hit limitations later:

This project uses Home Assistant OS — it is the official recommended installation and gives you access to every feature. You flash it directly to an SD card or SSD, just like Raspberry Pi OS.

What You Will Need

Step 1 — Flash Home Assistant OS

1. Open Raspberry Pi Imager.
2. Click Choose Device and select your Pi model.
3. Click Choose OS → scroll down to Other specific-purpose OS → Home assistants and home automation → Home Assistant.
4. Select the correct image for your hardware (e.g. Home Assistant OS 14.x (RPi 4)).
5. Click Choose Storage and select your SSD or SD card.
6. Click Next. Do not apply OS customisation settings — Home Assistant has its own first-run wizard. Click No if asked.
7. Click Write and wait for it to complete.

Step 2 — First Boot

Insert the flashed SSD/SD card into your Pi and power it on. The first boot takes 5 – 20 minutes as Home Assistant downloads and installs itself. This is normal — the progress bar in the web interface moves slowly. Be patient.

Open a browser on any device on your network and go to:

http://homeassistant.local:8123
# If that doesn't resolve, use your Pi's local IP directly:
http://192.168.1.xx:8123

You'll see a preparation screen while HA installs. When it finishes, the setup wizard appears.

Step 3 — Initial Setup Wizard

The wizard walks you through the one-time configuration:

• Create your owner account — this is the master admin account. Choose a strong password and store it somewhere safe — there is no password reset without console access.
• Name your home — give your home a name and set your location (city/country). This is used to calculate sunrise/sunset times for automations.
• Set your units — metric or imperial, 12/24-hour clock, currency.
• Discover devices — HA scans your network and lists smart home devices it found automatically. You can add them now or skip and add later. Don't worry if not everything is found — some devices need manual configuration.

Click Finish. You'll arrive at the Home Assistant dashboard for the first time.

Step 4 — Add Integrations

Integrations are how Home Assistant connects to your devices and services. Go to Settings → Devices & Services → Add Integration.

Popular integrations — search for these by name in the integration catalogue:

Step 5 — Install Add-ons

Add-ons extend Home Assistant OS with additional services. Go to Settings → Add-ons → Add-on Store.

To install an add-on: click it in the store → click Install → toggle Start on boot → click Start.

Step 6 — Create Your First Automation

Automations are the heart of Home Assistant. Go to Settings → Automations & Scenes → Create Automation → Start with an empty automation.

Each automation has three parts:

Writing automations in YAML

The visual editor generates YAML behind the scenes. Click the </> button in an automation to switch to YAML view — this is useful for complex conditions and for copying automations from the HA community forums.

alias: "Turn on lounge at sunset"
trigger:
  - platform: sun
    event: sunset
    offset: "-00:30:00"       # 30 minutes before sunset
condition:
  - condition: state
    entity_id: group.all_people
    state: "home"
action:
  - service: light.turn_on
    target:
      entity_id: light.lounge
    data:
      brightness_pct: 80
      color_temp: 400         # warm white (mireds)

Step 7 — Customise Your Dashboard

The default dashboard is auto-generated from your entities. To build a custom one go to Settings → Dashboards → Add Dashboard, or click the pencil icon on an existing dashboard.

Useful card types to explore:

Step 8 — Remote Access

To access Home Assistant from outside your home you have two main options:

Option A — Nabu Casa (simplest, ~£5/month)

Home Assistant's official cloud subscription. In Settings → Home Assistant Cloud, click Sign in and create a Nabu Casa account. Remote access is then available immediately with no port forwarding — plus voice assistant integration with Alexa and Google Home. The subscription fee funds HA development.

Option B — Your own reverse proxy with SSL

If you completed Project 1 (web server) and have a domain, put Home Assistant behind your Apache/Nginx proxy. Forward port 8123 internally and serve it at https://ha.yourdomain.com. Home Assistant needs one extra setting in its config to trust the proxy:

pi@homeassistant:~$ # Edit /config/configuration.yaml via the File Editor add-on:

http:
  use_x_forwarded_for: true
  trusted_proxies:
    - 192.168.1.xx     # IP of your web server Pi

Option C — WireGuard (most secure)

If you completed Project 4, just connect to your home VPN and access HA at its local IP (http://192.168.1.xx:8123). No additional configuration needed — the VPN handles the security.

Step 9 — Backups

Home Assistant OS has a built-in backup system. Go to Settings → System → Backups → Create Backup.

Automate backups with an automation:

alias: "Weekly backup"
trigger:
  - platform: time
    at: "03:00:00"
condition:
  - condition: time
    weekday:
      - sun
action:
  - service: backup.create

Troubleshooting Common Problems

Quick Reference