Eventhough most of my Aqara sensors are pretty stable - occasionally one or two of them jump off. And I don't notice until I log on to the HE bridge or test it.
How could I have a notification sent to my iPhone if these sensors haven't checked in w. HE for e.g. 24 hours.?
What driver are you using? All the community offerings I'm aware of have some custom attribute that can help you figure this out, then it's just a matter of using a rule or some app to notify you or whatever you want.
I was looking into and installing @bptworlds device watchdog - and can see the report stating e.g. 620 days since 'lastcheckin'. But got stuck there - not knowing what to do from there.
Isn't there still a "last check-in"-type attribute? That can be used.
A link would be great, but if my guess above is correct, this is a custom attribute you could use with, say, a Rule Machine rule. Trigger at either a specific time each day and see if the value is farther away than you want at that time (I'd use the Unix/epoch time option to make that easier), or even just trigger on that attribute changing and staying that way for so long, then notify.
I'd probably do something like the latter (or a third option, like the former but wait to notify) so I have control over when the notification happens. It's possible the app you found has an option for this, too, but I no longer use it.
I'm using this driver which is working well for me.
Gives a present/not present check for the device.
You can then have a rule to check for it going not present.
It is available vis HPM.
If you do write a rule to check for the devices going 'not present' you might want to put a delay before sending a notification as sometimes they can 'drop off' and go not present but come back on line again.
Just something to bear in mind and save needless notifications.
EDIT: This is something I have written in webCoRE.