This seems like a job for Smartthings and Webcore. While things like Alexa and ST itself have basic if/then routines, in my experience they fail miserably when you do anything outside the ‘if’ like god forbid, leave your house. That’s too many things for a smart product to handle (think fembot overload!).
So we all bought ST and built some basic “smart” things, only to realize we needed more on day 2. My day 2 realization that I needed smarter things consisted of what I thought was a fairly basic scenario:
While the garage door is open
if more than 15 minutes has elapsed
then text me / have alexa tell me /close garage door (or any combo of those)
UNLESS there is motion in the garage (i.e. me doing something in the garage, yard etc)
in which case wait 5 minutes and check again
If after 5 minutes later the garage door is still open AND there is no motion in the garage, repeat/loop above. You get the idea…
While it seems like a fairly normal scenario that any tool that calls itself smart should be able to do, it’s not remotely possible with most of them without some decent logic which none of these built for idiots products you can buy anywhere are capable of.
The vast majority of people want to tell Alexa to turn on and off a light. That’s what smart home means to them. That’s what manufacturers build to.
Here’s my webcore automation to handle the above. I originally had it close the garage door after at least 15 mins and no motion, but there were a few times I was unloading my car, had the hatch open, no motion, > 15 mins and webcore closed the garage. My garage is too small for me to drive in far enough for the hatch not to be completely inside and so the garage door scratched the hatch on the way down. Not bad though, which is why I just have it text me these days.
There’s still some random logic issue with it where it doesn’t keep track of time properly, but on the whole it keeps notifying me while the door is open > 15 mins and there is no motion.
Good luck and welcome to the world of webcore.