Re: Re: Tell me about 1-wire...

[Simon Haslam <simon_haslam@xxxxxxxxxxx>]

I've been pondering this too. I think you'd mainly use them at
physically s=
eparate locations in the 1-wire network - where you've got several sensors
=
close together it might be overkill (especially given that the sensor
chips=
are so cheap). I've bought some of those 1-wire metal probes which fit nic=
ely in the pockets in my solar cylinder, and will have some flow/return
etc=
sensors strapped to pipes - at the moment they're just pushed into breadbo=
ard but I think I'll shorten the leads as much as possible and then join
th=
em all back to a small junction box, which itself may have 2 RJ45 sockets
o=
n it (perhaps using one of Stuart's boards).

One concern is creating stars on the network (which wouldn't be the case
if=
each sensor was mounted on a twin RJ45 PCB) - hopefully it won't matter wh=
ere the sensor leads are only ~50cm long. For longer leads (e.g. I have
one=
to a DS18B20 I'm planning to install next to the weather compensation ther=
mistor for the boiler) I'm planning to run Cat 5 with DQ "up" to
the sensor=
on blue and "back" on orange (and likewise blue/white and
oracle/white for=
GND) - I've still not decided how to terminate that though.

This is mostly guesswork for me ;-)


Simon

--- On Tue, 2/11/10, leewild80 <muddyboots@xxxxxxx> wrote:

From: leewild80
Subject: [ukha_d] Re: Tell me about 1-wire...
To: ukha_d@xxxxxxx
Date: Tuesday, 2 November, 2010, 15:53

=A0 =A0 =A0 This may be a dumb question, but those PCBs with the twin RJ45
=
sockets - are they meant to be used one per sensor ?

IE each board provides a single connection point to the bus ?

I could imagine quite a lot of these being needed say, if I wanted to
measu=
re a number of points on my thermal store / pipework / manifold etc.

Or have I got the wrong end of the stick...

Cheers

Lee



=20=20=20=20=20=20


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