After using the Unlock Door on Open app (https://github.com/wesdeboer/smartthings-unlock-door-on-open), I wanted to update it a bit. The way I use this is to unlock the door between our house and garage when the garage door opens. A few years ago, there was a report that someone on our road had their garage door opener signal stolen (which I’ve heard is hard to do, and maybe even impossible) and were robbed (they didn’t have the door between the house and garage locked). Remembering this, I wanted to add a delay before the door unlocks, figuring that anyone who was trying to break in would want to get in immediately after opening the door. Adding a delay won’t affect our everyday use as it takes some time after pulling in the garage, getting the kids, etc.
Of course, the first question would likely be why not just unlock on presence? We do use our phones as presence monitors, however, as many people are aware, they aren’t always super reliable. Getting home while having your hands full after a long day and finding that the door was still locked and needing to get either your phone out or, gasp, a key out seemed, well, unacceptable
If the garage opener is older and not using a hopping code (aka rolling code), then anyone with the right tool to listen on known frequencies used by the door opener can record and then replay the stream of data that is being sent by the remote (even the outside keypad), meaning someone who’s close by could wait for such communication, and then later gain seemingly legitimate entry. Newer openers should use hopping codes. Which is why I find it safer for me to open the garage door via ST No such radio events But I’m a special case, my presence via iOS app works beautifully…
LiftMasterTM and Chamberlain companies offer this rolling code system since 1993. In 1996, they started to offer the Security+ System, and since 2013, they offer the MyQ technology Security+2.0 which allows to open and close your garage door with your smartphone. It’s the most practical technology yet!
Thanks for the link @ady624! Have to admit, I didn’t spend a bunch of time ever looking into it (yes, I should have!) but I feel a lot better after reading that article! Fortunately we do have a chamberlain manufactured after 1996 (but before 2013) so it seems we’re pretty safe from the standard rf hack.
We also have iPhones, and while the presence is good, it’s not spot on perfect (where it needs to be for WAF). Most of that probably comes from the spotty cell coverage near our house, but I’ve seen oddities where when we leave, if can take some time before it notices one, or both phones are gone. That being said, having the door sensors I already have in place allows for me to rely on the presence just enough to have it work well, and this smart app now fills in the last piece
No such radio events 
But I’m a special case, my presence via iOS app works beautifully… 