A door opens. Then what?
  1. TriggerDoor state changes to open
  2. CheckHas this opening already been handled?
  3. ActionPlay one short permitted audio clip
  4. StopWait for the next distinct opening
Concept map of Callum's experiment. No device connection or audio here.

The most useful thing I've done with Home Assistant is make it easier to get a drink of water. I'm tired, it's dark, and getting downstairs usually means reaching for lights or taking my phone as a torch. Now I can just walk through the house and the way lights up for me.

It's motion sensors and smart lights I ordered from AliExpress, connected through a Zigbee dongle to my homelab. The night-time behaviour follows sunset, so I'm not continually changing a fixed time as the evenings get darker. Such a small thing. I love it.

That's where I'd start with home automation: something you already do, made a little less annoying. The night lights are my own setup. The morning, movie and shutdown routines below are ideas you can build around your household, along with a completely unnecessary door project that already has its own build note here.

The walk downstairs is the whole point

A light coming on when something moves sounds almost too obvious to write about. But the useful part is the route through the house. You don't want to stop at each doorway and tell an app which room you're entering. You want enough light to see where you're going, without waking yourself up more than necessary.

If you're building a version of this, begin with one sensor and one light. Check where the sensor actually detects you. Walk towards it, past it and back again. A sensor that notices you after you've already reached the stairs is in the wrong place for this job, however neatly you've written the automation.

The darkness check matters too. Sunset gives you a changing reference through the year. Home Assistant's Sun integration can supply that information; a sun condition can then decide whether a motion event should turn the light on. Motion is the trigger in this example. Sunset determines when that trigger is useful. You can adjust the darkness rule if the room gets gloomy before the sun has gone down.

Spend some time on what happens afterwards. A second person might follow you, or you might stop halfway to pick something up. A short timer that blindly switches everything off can undo the whole benefit. Test a return journey and repeated motion before trusting the route at night. Keep ordinary lighting available while you're trying it out.

Sources: Home Assistant: Sun, Home Assistant: automation conditions.

Smart lights are a perfectly good place to start

My setup uses smart lights. I haven't had to replace the wall switches to get this working. Lights give you immediate feedback: you move, press something or change a rule, and you can see whether it worked. That makes them a lovely way into the software as well as a useful project in their own right.

Zigbee is the radio connection between compatible devices and a coordinator, which in my case is the dongle connected to the homelab. The exact device still matters. Check that the model you intend to buy works with your chosen integration before ordering a pile of sensors because the listing says 'smart'. Home Assistant's ZHA documentation is one place to check supported hardware and compatibility limitations; other Zigbee integrations have their own lists.

You also need to think about the existing switch. A bulb with its power switched off can't respond to an automation. Work out an arrangement everyone in the house understands, and test how the light behaves when power returns. The aim is to make the room easier to use. Nobody should need an introduction to your server before they can find the bathroom.

Sources: Home Assistant: Zigbee Home Automation.

Computer boards and cables on a workbench at Farset Labs
Photo credit Farset Labs

A morning routine you can skip

A gradual bedroom light is a sensible next experiment. Set a wake-up time, bring a suitable light up gently, and give yourself a simple way to cancel it. You can keep the first version entirely about lighting. There is no requirement to have the curtains, speakers and coffee all join in before you've decided whether you even like waking up this way.

Check that the bulb supports the transition you want. Home Assistant supports light transitions in scenes, but the light itself has to support them too. Try the change while you're awake so you can see whether the lowest brightness is comfortable and whether it fades or jumps.

The awkward case is a day off. Put a visible enable control somewhere you can reach, then test disabling the routine and changing the time. A routine that keeps its appointment after you've cancelled yours is going to get old quickly. Keep your usual alarm while you're experimenting; this is a lighting idea, not a promise that a bulb will get you to work.

Sources: Home Assistant: scenes.

Movie time, including the trip for snacks

Movie mode can start with one button that applies a living-room lighting scene. Set the lamps how you want them for watching, then save a separate normal-room scene to return to. That is already useful. You can add the television's playback state later if the integration exposes it reliably.

In a Reddit discussion about favourite Home Assistant automations, one person describes fading their media-room lights when playback starts and bringing them back when they pause. That's a good detail to borrow. Pause often means somebody needs to move around, and darkness stops being atmospheric when you're trying to find something on the floor.

Think about what should win if two routines want the same lamp. Your hallway sensor can carry on working while the living room is in movie mode, but a living-room motion rule shouldn't keep restoring full brightness whenever someone shifts on the sofa. Give that rule a condition to respect movie mode. Also check what happens when playback ends, the television becomes unavailable or somebody chooses the normal scene manually.

Sources: Home Assistant: scenes, Reddit: favourite Home Assistant automations.

The big shutdown button

There is something appealing about a button called 'lockdown'. For a first version, give it a very specific job: turn off the selected lights and stop the media devices you mean to stop. You know exactly which things it controls, and you press it when you're ready to finish up.

Write that list down before building the action. 'Everything' is a poor target when your router and Home Assistant server are among the things with plugs. Leave essential equipment alone. This routine doesn't need to operate locks or stand in for a security system to be useful.

The same Reddit thread includes someone who receives a reminder about their computer and chooses whether to hibernate it. Their reason is straightforward: the automation doesn't know how long they'll be away. That is a useful way to think about a shutdown button. Let it collect several deliberate actions into one press, with a clear result and an easy route back to normal lighting.

Sources: Reddit: favourite Home Assistant automations.

Or make your door behave like Family Guy

The Family Guy Door Transition is my contribution to the category of things that never needed to exist. Open a door, play a short transition sting, and entering the house gets a sitcom moment. There was no household efficiency problem waiting to be solved here.

The build note covers the door-state trigger, home automation logic and speaker output. If you're trying a similar idea, start with a sound you have permission to use. Decide how to handle a door bouncing between states, and give it a quiet-hours rule and an obvious off control. You want one joke when the door opens, not a soundtrack to somebody carrying shopping in.

It's also a good reminder that learning the trigger-to-action loop is enough reason to make something. You can use the same understanding for a helpful light later. Or keep making ridiculous things. There's room for both here.

Choose the bit you want to live with

The suggestions in home automation discussions get wonderfully elaborate. The useful test is whether an idea fits the people who live with it. My night lights work for an ordinary trip downstairs. Your best first project might be a lamp you can reach from bed, or a movie button that saves somebody hunting through menus.

Choose one room and write down what starts the routine, when it should stay quiet and how you override it. Then try the boring cases: somebody else walks in, a sensor misses you, the bulb is offline. You learn far more from those than from repeatedly demonstrating the one path you know works.

If you've got a version worth showing, bring it along. A short clip, a rough diagram or the story of why the light kept turning off will give people plenty to ask about.

Sources and further reading

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Try one room before automating the whole house. The planner gives you somewhere to keep the trigger, checks and manual override.

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