Ever needed to lock the deadbolt behind you but didn't have a key to the door? Admittedly, this isn't a problem you'll get into every day, but Instructables user Hextor has a clever solution should ...

A smart lock offers the benefits of a conventional deadbolt without the need to carry a physical key. Instead, many smart locks have keypads for PINs and/or electronic keys, where the “key” lives in ...