Home Assistant starter kit: your first 10 devices (and the automations to build)

Make your first Home Assistant project do something you’ll notice. A light comes on after dark. A door left open sends a reminder. A leak sensor gets your attention. Start with a small kit that gives you those useful moments, then grow from there.

Specs and setup steps from the makers and Home Assistant documentation.

Next, give a suitable plug-in device its own watt readings. Our smart-plug buying guide compares local Matter, Shelly and Zigbee metering, with washer notifications and standby-power projects.

Ready to make the leak sensor do more than send a message? Our automatic main-water shutoff guide adds a fitting valve actuator, the radio path and a damp-towel test plan.

Once your first automations are working, add a Zigbee scene button for all-off, reading lights or movie mode. A useful physical control makes the project easier for everyone to enjoy.

Ten devices, six purchases, one useful starting point

This kit counts ten physical devices: one host, one radio and eight sensors. The contact and temperature sensors come in three-packs, so you choose six product configurations rather than ten separate listings.

Your hardware	Devices	First job
Home Assistant Green	1	Run Home Assistant
SONOFF Dongle Plus MG24	1	Connect the Zigbee sensors
Aqara Door and Window Sensor, three-pack	3	Show open/closed status and send reminders
Aqara Motion Sensor P1	1	Trigger a light after dark
Aqara Temperature and Humidity Sensor, three-pack	3	Graph room conditions and send a temperature nudge
Aqara Water Leak Sensor	1	Trigger a leak notification
Total	10	Host + radio + eight sensors

Already have a suitable Home Assistant host? Keep it and skip Green. Your finished setup still has ten pieces; you’re buying nine new ones. Our mini-PC guide covers that host route.

Choose these sensors for different jobs, rather than filling the basket with ten copies of the same gadget. Contacts answer “is it open?”, motion starts an action, temperature builds a picture over time, and the leak sensor handles an event you want to hear about promptly. Pack quantities and exact configurations are listed in the Parts list.

For motion lighting, you also need a light already controllable in Home Assistant. That light and your phone are outside this kit’s ten-device count. You can start with the notification projects while you choose a light.

Start with the host, then give it a Zigbee radio

Green is the straightforward dedicated-host pick. It comes with Home Assistant OS installed. Connect its included power adapter and Ethernet cable, then follow onboarding in the app or browser. Have internet access ready for initial setup. The maker lists 4 GB RAM and 32 GB eMMC storage. See the official hardware page and installation instructions.

If you’re reusing a mini PC, finish the supported Home Assistant installation first. Get to a working dashboard before adding the radio or sensors. That keeps your first session focused: host first, devices second, automations third.

Use the SONOFF Dongle Plus MG24 as a Zigbee coordinator with ZHA, Home Assistant’s built-in Zigbee integration. Keep it on the Zigbee path for this kit. Our coordinator buying guide explains the separate Thread path and Ethernet/PoE alternatives; SONOFF’s ZHA instructions cover this adapter.

Put the dongle on a USB extension and use a USB 2.0 connection, away from USB 3.0 equipment. Add Zigbee Home Automation through Home Assistant’s integrations settings and select your adapter. Give that radio to ZHA; you can leave MQTT and Zigbee2MQTT out of this starter build.

Pair one sensor, name it, then do the next

Start a ZHA device scan and put the sensor into pairing mode using its maker’s reset instructions. Pair it where you intend to use it, then watch its state or reading before moving on. Home Assistant’s ZHA setup and placement guide covers pairing and USB interference.

Give each device a name you’ll recognise in an automation: Door A, Motion A, Room A temperature, Leak A. Those are example labels—choose your own in the interface. Use the same naming pattern for the remaining contacts and temperature sensors.

Here’s what each choice brings:

• Aqara Door and Window Sensor: a sensor and magnet give you open/closed status. Open and close the contact and watch the state change. Aqara describes magnetic separation detection.
• Aqara Motion Sensor P1: use its motion/occupancy entity for the lighting recipe. Position it for the movement you want to detect. Aqara documents sensitivity and timeout settings in its own app; use the controls exposed by your ZHA device page for this setup. P1 product details.
• Aqara Temperature and Humidity Sensor: put the three readings you care about on a dashboard. The maker specifies temperature, humidity and atmospheric-pressure sensing. Sensor functions.
• Aqara Water Leak Sensor: place it where water would collect, then build the phone-alert recipe below. Aqara’s manual describes water and flooding detection.

Pair these Aqara sensors directly with ZHA.

Keep the first network compact. Battery end devices aren’t mesh extenders, and ZHA documents compatibility issues between some Aqara devices and some Zigbee routers. Add a supported mains-powered router when you need to expand coverage, following the ZHA guide’s recommendations.

Build your first automation in the visual editor

Go to Settings → Automations & scenes → Create automation → Create new automation. The editor documentation walks through the interface.

Think in three pieces: When something happens, And if the conditions fit, Then do the action. Home Assistant’s automation basics explains how those pieces connect. Name each recipe after its outcome so it’s easy to find later.

The timers and temperature below are example settings for you to change. They’re starting choices for these recipes.

Motion lighting: make the P1 useful after dark

Choose a light already added to Home Assistant, then create this automation:

1. When: the Aqara P1 motion/occupancy entity changes to detected.
2. And if → Add condition: open the Sun group and choose Sun is set.
3. Then do: turn on your chosen light.

Sun is set passes from sunset until sunrise. The Sun condition guide points you to this current UI option. Try the light action by itself, then walk through the sensor’s detection area after the condition is met. Now you’ve got a practical reason to stop reaching for a switch.

For a simple light-off companion, make a separate rule: when the P1 reports clear continuously for two minutes, turn that light off. Choose State changed as the trigger and put the duration in For at least. Choose a longer interval if you want the light to remain on while you’re still. A motion sensor responds to movement; save seated-presence projects for the coming mmWave guide.

Leak alert: get the message onto your phone

Install the Home Assistant Companion app, connect it to your instance and allow notifications. Send yourself a test message first. Under Then do → Add action, find your phone’s notification action (notify.mobile_app_…) and fill in Message; the Companion documentation describes targets beginning notify.mobile_app_ and the required message field.

Build the leak recipe with the Aqara Water Leak Sensor:

1. When: its water-detection entity changes from dry to wet.
2. Then do: send your phone a message such as “Leak A detected water.”
3. Test: use the maker’s test procedure, watch the sensor state change and verify that the message arrives on your phone.

Keep the message short and identify the sensor. Standard phone push can use external delivery infrastructure; keep sensitive details out of notification text. The Companion delivery documentation explains that path.

This starter recipe alerts you. Automatic main shutoff is a later project with its own valve hardware and installation requirements.

Door-left-open reminder: let the contact do the remembering

Use one Aqara Door and Window Sensor and the phone action you already tested:

1. When: the contact changes from closed to open and stays open for five minutes.
2. Then do: send “Door A is still open.”
3. Test: open it, close it before the interval ends, then try leaving it open for the full interval.

Choose State changed, select the contact as Entity, set the closed-to-open transition, and enter five minutes in For at least. A state trigger watches the transition; if the door is already open when you save the rule, close and open it to start the test. Adding video at the entry? Our PoE cameras for Frigate guide covers the camera and stream choices.

Start with Home Assistant’s state-trigger reference; its detailed setup page explains that duration timers reset after a restart or automation reload. Retest the reminder after editing it. Repeat the recipe for the other contacts once the first one feels right.

Temperature graph and a heating nudge

Start by adding the three Aqara Temperature and Humidity Sensors’ temperature entities to a history graph card. Replace the example entity names below with the ones on your device pages:

type: history-graph
title: Room temperatures
entities:
  - sensor.room_a_temperature
  - sensor.room_b_temperature
  - sensor.room_c_temperature

The graph helps you see changes over time. For an action, add this separate temperature nudge:

1. When: Room A temperature crosses below 18 °C / 64.4 °F and stays below for ten minutes.
2. Then do: send “Room A is cooler than your chosen threshold.”

Enter the threshold in the units your sensor displays. Under When → Add trigger, choose Numeric state crossed threshold, select the temperature Entity, set Below, and enter ten minutes in For at least. The detailed numeric-state guide explains threshold crossings: the trigger fires when the value crosses the threshold, rather than repeatedly while it stays below. Let the reading move back out of the range before testing another crossing.

Pick the threshold for your comfort. This recipe gives you a heating reminder; direct thermostat control can come later. You’ve now got four useful starter projects, plus the small light-off rule, using every sensor type in the kit.

Finish the evening with a test and a backup

Use Run actions to exercise a light or phone action, then trigger the actual sensor transition to test the whole recipe. Open the automation’s trace to see which trigger fired, which conditions passed and which action ran. The troubleshooting guide helps you follow the real run. Its linked testing guide explains that Run actions assumes the top-level conditions were met; conditions inside actions still apply.

Create a Home Assistant backup and keep a copy separate from the host, with its backup emergency kit. The backup instructions cover that process. ZHA also has network-backup options for your radio setup.

Then stop shopping for a moment and enjoy the useful bits you’ve built. Adjust a timer, rename a confusing sensor, or put the graph where you’ll see it. When you’re ready for the next project, head back to the Home Assistant hub.

Ready to make your contact and motion sensors work together? Build a DIY home alarm with Alarmo for Away, Home and Night modes, a siren and phone alerts.

If your motion lights go dark while you sit still, our presence-sensor buying guide compares the upgrade paths and adds desk-lighting and bathroom-fan recipes.

Ready to put those temperature sensors to work across more rooms? Our room-by-room temperature and heating guide adds room graphs, a cold-room nudge and a weekly temperature report card.

Ready to choose the lights for those motion rules? Our local smart-lighting guide compares bulbs, wall dimmers and scene buttons, then adds sunset and movie scenes.

Shopping for someone else’s next project? Our homelab and smart-home gift guide matches sensors, hosts and bigger upgrades to the person who’ll enjoy building with them.

Ready to put floor cleaning on the dashboard? Our robot vacuum guide separates local Matter commands from cloud maps and room tools.

You can also give an existing network printer a useful voice. Our Brother SNMP guide adds toner/drum monitoring and a low-toner reminder, with printer picks if you need new hardware.

Want to assemble your own host instead of using Green? The Pi 5 kit and parts guide helps you choose the board, power, cooling, storage and case that belong together.

Once your devices have clear names, our local voice hardware guide shows how to expose a light to Assist and give your commands a dedicated microphone and speaker.