I want to install an electronic lock on my office/workshop that only a specific individual(s) can unlock. I want it to lock every time the door is closed and the room is empty but I do not want to have to use a key or pin code every time I open it.
So I am thinking of designing a system that detects close proximity to the door for authorized users, and unlocks it. Allowing authorized users to walk up and open the door. The system would also need to know when an authorized user was actually in the room, and keep the door unlocked until they leave. This should be manageable with motion sensors and computer terminal usage (registering that someone is using the computer equals someone is in the room).
What kind of solution would be necessary to accomplish this?