This is a really nice guide, and covers everything from source source to sea, so to speak.
Ideal for someone installing for the first time, thanks for sharing!

Security wise, while I love automating everything, I personally would just give them a physical key to the front door. (Or an RFID keyfob system).
What you’d be achieving is the equivalent of keyless car entry, with the additional downside that your son can’t choose not to open the door if something sketchy happens.
And instead of entrusting them with a traditional key that they can treat responsibly, you’re just putting something in their backpack that they don’t have to think about.

If you really want to do it, basically anything in homeassistant that has wireless capability and a state would probably work.
A zigbee radio, and pretty much any device doing anything would do it.
When device_name becomes available, activate door opening.

That’s a pretty neat bit of kit. If they did it in metric sizes, I’d be tempted.

Your meter may have some kind of magnetic flux that occurs as the dial spins, which you might be able to sense and interpret.

I’m curious to hear what people come up with, as I quite fancy one too.

I would be wary of installing anything that actually touches the water that doesn’t come from an accredited manufacturer, however. As you don’t want Ali-express grade metal in your drinking water.

Which unfortunately means the options will be either expensive, or building off the back of other equipment currently installed (water meter, etc).

It was broken for a few weeks of 2024.2 (I think). I ended up learning how to do a manual downgrade while they fixed it!

Asking questions is always good, don’t worry! Feel free to ask more, heck update the thread and ask questions as you go along if you like.

If you list the devices you want to migrate, I’m sure the community will happily highlight any tips, or which will be the easiest to get you started.

It is indeed! Mostly just fiddling around with the settings.

@smeg@feddit.uk, here is a paste of the config so you can play with it:
(If you click show code editor, then paste in, you can then go back to visual editor with things configured)

Speedtest needle gauges and ping with colour change:

type: horizontal-stack
cards:
  - type: gauge
    min: 0
    severity:
      green: 80
      yellow: 50
      red: 0
    entity: sensor.speedtest_download
    max: 100
    needle: true
  - type: gauge
    min: 0
    max: 20
    entity: sensor.speedtest_upload
    severity:
      green: 16
      yellow: 10
      red: 0
    needle: true
  - type: gauge
    min: 0
    entity: sensor.speedtest_ping
    severity:
      green: 0
      yellow: 15
      red: 20
    max: 100

Air quality with lots of different colours:

type: horizontal-stack
cards:
  - type: gauge
    entity: sensor.oxford_air_quality_index
    needle: false
    min: 0
    max: 500
    segments:
      - from: 0
        color: '#00e400'
      - from: 51
        color: '#ffff00'
      - from: 101
        color: '#ff7e00'
      - from: 151
        color: '#ff0000'
      - from: 201
        color: '#8f3f97'
      - from: 301
        color: '#800000'
    name: 'Air quality: PM2.5'
    unit: µg/m3
  - type: gauge
    entity: sensor.external_environment_f
    max: 40
    severity:
      green: 18
      yellow: 25
      red: 30
    needle: false
    min: -10
  - type: gauge
    entity: sensor.oxford_uv_index
    max: 10
    severity:
      green: 0
      yellow: 3
      red: 6

Once you’ve got your head around horizontal stacks (lets you put multiple small dials together), it’s mostly picking thresholds and settings colours.

Currently, it’s using a Waze integration.
The coolest thing, is that it’s given me a really nice data set for when are the bad times to drive across town are. (Sadly, it’s during the morning and afternoon school runs).
It also reveals that the travel time on average is impacted significantly by the school holidays, and the weather.

My “What’s the internet connection up to?” card:

My “Leaving the house” card:

It’s nice to compare the local predicted temperature, and local sensor.

I’ll pop this as a top level comment, as so many people have made recommendations, thank you everyone!
Valetudo absolutely sounds like the way forward.

After more digging, it looks like mopping, unless you spend lots of money, is kinda basic on all models.
So I’ve gone with a basic second hand machine that works with Valetudo, and has simple mopping.
Hopefully it’ll let me get a good idea of what is/isn’t possible, and if a £600 full on mopping device is worth it!
And who knows, if spending that much is worth it, I can have one on each floor, like a fancy rich person.

(I also need to find out how well machines deal with poo!)

I have done this for my leak detectors.
Almost everything else obeys DND, but water? That’s gonna wake me up.

Haha, I have no idea. Possibly less corporate, more “small, simple, open system that others can contribute to”.
I can only speak in vagueness on the “european-ness”, to be honest.
HASS/Zigbee have an open, european feel to me.
HomeSeer has a very american “this is the way we’re doing it, it costs this much” feel.

I plan to put guards on.
However, I’m first treating it as a service problem (if someone in the house is using the physical switch, I haven’t made it easy enough to use the controls, and more hardware may be required)

Exactly this.

My temperature sensors don’t need to phone home or even communicate two ways. They just need to squawk the temperature into the ether.

For me, I just turned them on, pressed the button for 5 seconds, and added them to ZHA.

I’m pretty sure Tuya are just keen to get people in their ecosystem/potentially avoid having to give tech support for HASS. And I honestly don’t begrudge them for that.
It should be possible to connect all Zigbee devices to another radio. From there, it’s just software integration, which for popular devices/chipsets is generally very good.

That, and I haven’t actually got up to replacement yet, as there were rooms that didn’t have a sensor.
I think I’ll experiment with adding an AA/AAA battery holder to the ZB02 next. If that ends up being too much of a faff, I might just sell them off cheap, and use the money to change to AAA sensors.

You’re right, I should have considered that. Thanks. Edit: Edited.

This is my opinion on things.
ZHA support for Hue bulbs is good, but there are swiss-cheese holes. For example, you can’t set power-on behavior on the RGB bulbs I have.
I like to set this, as coming on at 80% power by default should (I hope) increase the longevity of a £25 (full price £50!) lamp.

Hopefully, this will inspire a flurry of fix tickets, and people contributing.

As for the bridge, there is a caveat to just leaving it connected to HASS and not using the app: If Signify/Philips ever make a BIG change to the way the interaction works, unless HASS set up two-mode operations with the hub to cover legacy support, people may end up having to update their hub to use the latest version in HASS.

I’ve been using a Tuya zigbee one.
The sensor is a plastic block with a mounting screw hole, and two metal contacts on the base.
Water hits the contacts, it transmits an alert.
Sensor is on a wire, attached to the transceiver and battery, so it can be put out of harms way.

Fired straight up in standard ZHA under HomeAssistant.

It cost about £14