Count entry and exit Edit
Place IR before door post and one just after door post. An entrance is triggered by the first beam and an exit be the opposite second beam. If five people walk into a room the two beams will break and count them entering. As they leave the beams are broken in reverse order and they are counted leaving the room. The CompHomeAutomation system knows how many people are in a given room at any time switching the battery operated LEDS.
Hanging the washing Edit
Install as many InfraRedLeds inside a perimeter hundreds if possible. You go out the backdoor to do the washing and have to break a sequence of beams in a specific order before you get to the washing line. Lets presume you are alone , thus any breaking of a beam out of sequence would indicate an intruder.
The difficulty is in compensating for multiple people at home and indicating where they are individually.