In article , Neil Jowsey
writes
Hiya,

I have an outdoor twin 'security' light that has a PIR that will switch the
light on for a short period of time if triggered my motion after dark. This
used to work ok, it still had a number of triggered false alarms when the
lights would come on for no apparent reason, but it was just about
acceptable.

I've since fitted a car cover to one of my cars. This does flap in the wind
a bit and means the damn light's almost never off at night as it keeps
triggering the PIR :-(

I'm looking for a more intelligent PIR and daylight sensor that can operate
the existing lights or maybe a sensor and light set. Can you get more
intelligent PIRs that only operate on say, human body heat, rather than the
motion of trees or the flapping of car covers in the breeze :-) Does anyone
have any recommendations?

You can't. It's just seeing a difference in heat.

The best you can hope for is to either move the PIR so it can't see what
is triggering it;

or you can mask off areas of the PIR lens using black tape to prevent it
sensing things in some areas. If you look at the lens you can see
"segments" on it, each of these segments is a crude fresnel lens giving
sensing in a certain area.
--
Tim Mitchell