Re: Occupancy detection

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
news:46b39c57.2071010625@xxxxxxxxxxxxxxxx
> "Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:
>
> >The RF range has decreased over time, and I did not mean to imply it's
from
> >the RF detectors "saturating" the environment.  There are times in the
> >morning now where the X-10 RF flat out doesn't work unless you put a
Palmpad
> >or keychain remote within a few feet of the transceiver.   Whether these
> >blackouts are caused by sunspots, military transmissions or whatever, I
> >can't say.  Without an RF meter it's just guesswork.
>
> So just how close to the Naval Observatory are you?

Apparently too close.  I also believe I am in a straight line path between
two large military installations active in Homeland security work.  From
what I can see each has several huge towers with all sorts of different
antennas pointed my way.  Not sure what bands the transmit on or even if
they are involved but the blackouts are becoming more and more frequent.

At first, I thought there was something wrong with the wireless thermometers
and kept changing batteries only to find they hadn't run down more than half
a volt.  That's when I noticed the bathroom lights would misfire, despite
the close proximity of the TM751 to the Hawkeye.  I'd reset all the
thermometers so that they had blank displays and when they finally
refreshed, the RF "storm" seemed to be over.  The bathroom light goes on and
off nearly instantaneously when the RF skies are clear and becomes quite
erratic when the thermometer displays "lock up."  I can only assume it's a
stronger signal drowning out the flea-powered devices like the Hawkeyes and
the thermometer transponders.

For me, the really bothersome part of the problem is that in many, many
cases, the darn things work just fine.  You can hardly get more bang for
your buck, especially if, like me, you got the X-10 gear with the vouchers
they used to hand out like candy.  To get to the next quantum level of
reliability means you have to basically leave the X-10/RF world and go
multiple sensor and hard wire or an use RF protocol that's two way with
collision detection.  Even so, my front tooth, my costochondral separation
and my patella are working hard to convince me that near the Nation's
Capital I might be wise to cut RF completely out of the loop if I want to
maximize reliability.

I have *so* many Hawkeyes that I'd be willing to try hacking a few to
disable the RF transmission feature and use their output to close contacts
or otherwise act as sensors in a hard-wired system.  Or I might decide that
the X-10 RF component can act as a secondary or tertiary sensor in a
multiple sensor setup, with the primary motion detector being the hardwired
broken IR beam sensors.  I like the beam because it's immune to all but
leaping pets, flying bats and couples crossing the barrier "in flagrante
delicto."

The problem becomes how to integrate the critical lights into the X-10
system while maintaining isolation from some of the typical X-10 problems of
collisions, inadvertent activations and lost commands.  I'd like to still be
able to turn all the houselights out with a single button press but that
feature makes the stairway lights vulnerable to someone pressing the ALL
LIGHTS OFF switch while someone else is descending the stairs.  The
stairways lights should only respond to X-10 commands if no one is using the
stairs.

--
Bobby G.