Evening klogg,
There are a few ways to do what you want of the top of my head and I am sure many, many others off the top of othersā¦
I quite like using Apple Home app to use services outside my home. But this will depend on if you have an iPhone and a old iPad (iOS 10.x) or Apple TV (one below 4k) / Apple TV 4k (You will need an iPad/Apple TV to use the Home App outside your home)
I use a raspberry pi to run āHomebridgeā and there are some nice simple guides to setting it upā¦ Link
This will also give you feed back to what is turned on / off / state etc depending on if you have exposed it to home bridgeā¦ the advantage of this is itās behind Apple authenticated through your secure iCloud and quite a nice app to use.
As also mentioned above. VPN could also be a good option for youā¦ This will give you your HA as it exists nowā¦
However only enable it when you need to (your away) - your router will most likely have an option for thisā¦ please understand the risks behind doing this and the protocols being used, its very easy to fall into a trap of false security because your using VPN - If you go don this routeā¦ think about DNS. There are several free options but you dont want to go away and find your IP changes - but you can always get HA to ping you your new IPā¦
Using an MQTT broker (i.e. CloudMQTT) your HA can then pull your message and act (i.e. turn on / off run automation) - I do this a lot but use Node Red to do the automation routineā¦You can then get a MQTT message back to say x, y has been run / stopped / state or a notification. There are several MQTT publishing apps you could use from your phoneā¦ Its a very fast, lightweight way of reliably getting info back and forthā¦ since I know zero about irrigationā¦ you could send message for the status of your irrigationā¦ then get a notification back to your phone āNeeds waterā and send a message to water - sorry thats the extent of my knowledge on irrigation.
Using calendar services is a way to automate a schedule but there are several others. One advantage of a calendar is that you use your phone to set the event to start and stop with a moments notice depending how you setup HA/NodeRed etcā¦ However it has the downsides with schedules.
You donāt say how you get the data position of mapping peopleā¦ iCloud, Owntracks etc?
I mostly use NodeRed to run most things and use HA and a source for devices. Do you use any other services or just HA?
Why is it not a automated function though? Needs water -> water -> enough water -> stop water -> send notification āWatered whatever - used 3.4 litters of water - time started 2:30pm time stopped 3:30pmā
One more thingā¦ what happens if there is a power cut? do all your services power on correctly? will you know? using something to monitor your systems (raspberry piās are good for this) and restart services etc - UPS / NUT ā¦ Super important if you use Docker especially on some NAS systems.
Dont want to see you go on holiday to find all your systems are down 2 days later