"DerbyDad03" wrote in message
news:d15743c6-7dca-4152-9d4b-

stuff snipped

"I'm betting when DerbyDad adds a second light to his setup, he'll
meet X-10's now infamous "PlusOne" demon."

errr...you might as well tell me about it now.

And ruin the fun? The PlusOne demon will put hair on your chest! It will
cause you to utter swear words you didn't even know you knew!

My initial set up is a dual flood over the garage door on a 3-way
switch and a fixture by the front door controlled by a single switch.
The single and the main 3-way are in the same box by the front door,
the 3-way companion switch is in the garage.

So far, placement of the sensor at about 4 feet (6 didn't work)
catches my van as I pull in and pedestrians as they walk past the car
if it's in the driveway.

This is probably one of the most important reasons I chose to use a
standalone fixture. IIRC, it was $10 for the whole shebang and it included a
sensor on a stalk that you could aim right at the walkway. The X-10 sensors
tend to take in too much, no matter where you place them and the "stock"
mounting arrangement is very limited (flat against the wall, basically).

I've been most successful with them in the bathroom and outside, positioned
looking across the basement stairs from one side to another so that only a
person walking right by would trigger it. Aiming it at a blank wall also
reduces squirrel, bird and wind activation. Mount yours on a swivel joint
(shouldn't be hard for a soapbox racer builder!) so you can point it just
where you need it. Be prepared for it to miss sensing anything when the
outside temps are in the 90's. Not enough difference between warm living
bodies and the background, I guess.

If you're in a cold neck of the woods, use lithium AAA's to make sure they
work below zero degrees. I have taken one or two of the hard to reach ones
and soldered in "D" cell battery holders remotely located from the sensor.
Another thing I dislike about the sensors is that when you change the
batteries, you lose the settings. A remote battery pack allows me to clip
in two AA's in a holder into the circuit to keep the memory settings alive
while I change the D cells. For the sensors located high up, that's a real
help. FWIW, I've had one unit running off 2 D cells for over 5 years. The
sensors are pretty low-drain affairs.

What's this "PlusOne" demon you speak so fondly of?

Oh, what the hey. I'll spill. The X-10 motion sensors have, in addition to
the PIR motion sensor, a cadmium sulfide (CDS) cell to detect light. When
they sense that it's gotten dark, they will turn on the lamp that has a unit
setting ONE higher than the code it is set to. If it's controlling lamp A1
then at dusk it will turn unit A2 ON and at dawn it will turn A2 OFF again.

You can't imagine how badly this has bewildered many new users of X-10.
Even the really smart guys get taken in, and worse yet, those who think
they've gotten around the problem by choosing unit code 16 (the highest
allowed) find that the PlusOne demon "wraps" around and will use unit code 1
as the dawn/dusk unit.

Perhaps the worst case scenario is a situation where a PlusOne sensor is in
range of another and the codes are set so that one sensor turns out the
lights and the other sensor, thinking it's dusk, turns them back on. The
potential for insanity is very, very high.

The light detection circuitry is actually quite handy when you know it's
there and how to deal with. Most times, though, it's more trouble than help
so I open the motion detectors, find the CDS cell (the silver can with the
red squiggly lines on the glass top), and cover it in black shrink tubing to
defeat PlusOne completely. Some people cut the leads, but the shrink tubing
method is more easily reversible with a quick touch of an X-acto knife.
Advanced users have created many "mods" that allow you to clip out the CDS
sensor and replace it with other detectors for a wide range of purposes. I
have about 40 of them because when I was acquiring X-10 gear, they always
threw in a couple of "Hawkeyes" for free.

I've had some success in eliminating squirrel-caused activations by using
strips of black masking tape on the smoked plastic "lens" of the motion
sensor. Even so, I much prefer my $10 standalone motion detection fixture
just to keep all the extra X-10 signals that come from detecting rabbits,
squirrels, cats, dogs, birds, bats and passing cars from cluttering up the
powerline. The X-10 motion sensors are perhaps the number one cause of lost
transmissions due to collisions. X-10's error checking protocol is
unfortunately not the best so when two valid commands appear on the line at
the same time, they often create a third command that may or may not effect
other modules in the house.

I discovered collisions when the motion controlled light in the bathroom
would come on when you entered the room and then it would suddenly kick off
at pretty much the worst possible moment. That had SUCH low SAF I pulled
ALL the X-10 motion sensors from the first floor except for the bathroom
one. Since I've started using the HomeVision controller, I've been able to
set it up so that at night, the bathroom light comes on at 25% dim and goes
out when no motion is detected for 16 minutes. There's still some arm
waving on the can from time to time, but no more lights out in mid-stream!

Welcome to the wild and wacky world of X-10, Derby. Despite the horror
stories, I can't imagine living without it and when I visit other people's
homes, I feel like I am in the stone age. I used to be evangelical about
pushing X-10, but now I've turned 180 degrees and mostly warn people off
unless they are prepared to get deep into the details. It's not as easy as
X-10 makes it seem, but it's also not as bad as its detractors would have
you believe. Like many other things, it takes patience, learning and skill
to master.

--
Bobby G.