RE: 1-Wire network wiring

["Nigel Giddings" <nigel@xxxxxxxxxxxxxx>]

Jim,



Thanks for the introduction....



As you know I have cabled for temperature sensors everywhere... I have
to admit not all the sensors are installed yet either... All though the
cable is...



At the moment this is not helped by my broken leg which has a very
limiting effect on installing cables (and Temperature Sensors).



I have fitted reed switches in all internal and external door frames,
and all windows. As mentioned this only gives Closed or not closed
status, not how open it is... I also have one and sometimes two
temperature sensors in each of the rooms, at least those with completed
sensors. It is surprising how you learn what is happening in a room by
the small changes in temperature. Only this week I was able to see that
the lights had been left on in the cinema area in the basement because
of the temperature rise. I can also tell whether doors are open or
closed by the way heat collects and moves around the house. Even sitting
in the study, as I am now, can be seen as the PC and I have raised the
room temperature from about 21.2 C to 22.4 C since I sat down this AM. I
am sure this is due to relatively high insulation levels so it may not
be the same in all houses.



I have looked at using one wire to monitor switch position but using 1
wire has a few limitations. When measuring temperature the bus is
scanned every minute for known sensors so there is no issue with
collisions of data. When monitoring switch positions the data is fired
as the event (door closing) occurs. This could lead to collisions,
especially if on the same bus as the temperature sensors. I am using
VIOMs switch inputs and also for switching O/Ps via Homeseer. I would
use the xAP enabled NETIOMs now but I started before they were
available.



Nigel



-----Original Message-----
From: Jim Noble [mailto:yahoo-groups@xxxxxxx]
Sent: 25 October 2007 12:10
To: ukha_d@xxxxxxx
Subject: Re: [ukha_d] 1-Wire network wiring



Chris Hunter wrote:
> Thanks - I was toying with the idea of a pervasive 1-wire
temperature-sensing network around the house (which is just a shell, at
the moment) as a way of detecting doors open etc ... picking-up on Tim's
idea of thermostats on pipes (in anorther thread) ...
>

Room by room temperature sensing would be very useful to have (cue Mr
Giddings... :-) but I suspect it would be a lousy way of reliably
detecting open doors.

If your house is at the shell stage, surely it would be better to wire
for some sort of door/window contact closure sensors...? (Could still be

1-wire based...)

Jim





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