I have a bunch of presence and motion sensors (like four, but shush) and when people leave rooms I would like to turn the lights off after five minutes, however if someone returns to the room before that five minutes is up, I'd like to start that countdown again. Is there a grateful way to do this that isn't me just doing if no activity for five minutes, turn off the lights, else wait five minutes and then turn off the lights. Because that's ugly, rigid and not very smart at all.