Thinking of possible Halloween projects - having things with motorized turnable heads in my yard, which would turn to face (and track) people as they walk past my house and up to my front door.
But to do that I need to know where people are on the sidewalks. There's of course the street sidewalk that goes past the whole yard, then in the middle of the yard there's a (straight) sidewalk to the front door, perpendicular to the street sidewalk.
Is there a good way to for a Pi to sense where people are?
I've thought about a few PIR type sensors, but that would give very low resolution unless I put in a LOT of them.