RE: 1 wire temperature monitoring

["Nigel Giddings" <nigel@xxxxxxxxxxxxxx>]

Hi Ben, and others who have responded,

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I have uploaded a couple of files to the 'files area'.=20

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http://groups.yahoo.com/group/ukha_d/files/Corbenic/

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One is a picture of a typical light switch in my house. All the light
switc=
hes are double gang with either 4 retractive switches or 3 and a 'hole'
for=
the DS1820. The picture is of a 3 gang plate with the hole in the 'Study'.=
Each room has one light switch plate with a ds1820 fitted. More ds1820s ar=
e placed in hidden locations, or as in the basement just hanging from the
c=
eiling...

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I did not mount the ds1820's in any form of grommet they are just floating
=
there using the tension of the CAT5e to hold them in position from behind.
=
The ds1820s are round with a flat side but this does not notice (at least
t=
o my eyes).

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The issues here are: is the wall plate acting as a heat sink and reducing
t=
he response of the device? Optimum thermostat position is not typically
the=
same place as the light switch, and of course personal choice as far as ae=
sthetics.

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The second file is a PDF showing the position of some of the ds1820s and
th=
e cable run for the basement and Gnd floor. As I mentioned I have used
CAT5=
e. I have wired in such a way that the devices are across the wires and
all=
wiring is in series. You will also see reference to 8 way connector blocks=
with screws (shown as red boxes on the PDF) which are the house alarm vari=
ety from Maplin. This are a bit of a PITA to install, lots of wiring, so
wo=
uld probably use a punch down version if I were doing it again.=20

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The idea is that the GND connection comes into the Junction Box on the
Gree=
n and Brown pairs, goes up the branch on the Green pair and returns on the
=
Brown pair to the ongoing Green and Brown pairs to the next Junction Box.
T=
hat way I do not end up with long spurs, all the wiring is in series. I do
=
similar with the Vdd and DQ lines, thereby not relying on parasitic power.
=
Hope this makes sense.

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The ds1820s are wired as shown in the PDF and I use heat shrink to isolate
=
the legs with an overall wrap to give it some strength. Because the holes
i=
n the wall plates are just big enough for the ds1820s the overall heat
shri=
nk stops the thermostat pulling through the hole.

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You can see I have noted the serial numbers on the drawings so that they
ca=
n be easily identified during setup in Homeseer, I use the mcsTemperature
p=
lugin.

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Any more questions just shout.

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Nigel

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=20

-----Original Message-----
From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of B=
en McCormack
Sent: 03 January 2009 20:08
To: ukha_d@xxxxxxx
Subject: Re: [ukha_d] 1 wire temperature monitoring

=20

Nigel

Thanks for sharing this.

Our house currently has many holes in walls and ceilings and I have=20
been thinking about 1-wire for temperature monitoring. This hub seems=20
perfect.

I do have a couple of questions

How do you mount the sensors around the house? Has anyone found=20
anything easy to use?

I assume I you use Cat5 cable to loop into and out of each sensor. I=20
guess you 'splice' the sensor onto the Cat5 cable at a suitable point?

Ben

On 3 Jan 2009, at 15:33, Nigel Giddings wrote:

> Hi,
>
> I have been looking at extending my 1-wire temperature monitoring
in=20
> the house. 1-wire was never designed for long cable lengths and=20
> begins to suffer reflections if the cables get too long... well I=20
> have reached that point.
>
> I want to monitor some of the H/W pipes to things like the showers=20
> and baths, to trigger towel rail heating and also temperatures on=20
> the heat exchanger to see if it actually exchanges heat as well as
a=20
> couple more room and equipment rack probes....
>
> However, I have run up against the cable length issue.
>
> What I have found is a Hub that effectively separates three daisy=20
> chains of sensors to enable three lengths of cable with sensors.
>
> http://www.homechip.com/catalog/product_info.php?cPath=3D22&products_id=
=3D109 <http://www.homechip.com/catalog/product_info.php?cPath=3D22&product=
s_id=3D109>=20
>
> What is also nice about this is that it connects to the PC via=20
> Ethernet so you can remotely position it wherever you have Ethernet=20
> connectivity, even over the internet....
>
> I intend to use with Homeseer with a plug-in called Ultra1wire to
do=20
> all the leg work and place the data into virtual devices in
Homeseer=20
> which can then be used however I want.
>
> http://forums.homeseer.com/forumdisplay.php?f=3D854
<http://forums.homese=
er.com/forumdisplay.php?f=3D854>  ($29.95)
>
> They are in stock, spoke with them today, and will probably order 1=20
> on Monday (=A399 + VAT + P&P =A37)
>
> Just thought I would pass it by the list to see if any other=20
> alternatives exist....
>
> Nigel
>
> [Non-text portions of this message have been removed]
>
>
>=20

[Non-text portions of this message have been removed]

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[Non-text portions of this message have been removed]


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