When you say “when I enter”, do you mean when you enter your home, or when you enter the room?
Using a mobile device as a presence sensor by itself will not give you the location accuracy needed to track your movements from room to room. You would need another technology such as iBeacons to do that.
Refer to this thread if you want to explore iBeacons with SmartThings:
By itself, the iPhone 6 as a presence sensor should be able to track whether you are home or not (or at least within close proximity to your home, though people have varying degrees of success with this). But don’t expect it to track where in your home you are.
Adding iBeacons should dramatically improve both situations, however. It should track whether you are home or not very, very well and, with enough iBeacons set up with appropriate power levels, be able to track your presence (or perhaps more accurately, your phone’s presence) from room to room.