Re: 1 wire temperature monitoring

[Kevin Hawkins <yahoogroupskh@xxxxxxxxxxxxxx>]

Nigel Giddings wrote:
> I like the look of OPNODE, any idea of price? I will drop them an
e-mail to ask....
>
> <snip>
>
IIRC they are similar in cost , and the Euro rate isn't helping so they
could be even more expensive as it's a Spanish company .  I think as the
three legs is important then the other solution will be more economic.
I know Daniel , the developer, made some changes to support some 1-wire
hubs which may be an alternative , but I have also seen a few posts on
the mcs forum with regard to sensors disappearing or being transient
with hubs (hub related - nothing to do with OPNone).  I've never sussed
whether that's just 1-wire magic or a hub related issue, and have just
been thankful that I've not seen the issues (except with HomeVision).

One user on the mcs forum who had 1-wire network stability issues moved
to OPNone and they went away but then he had another problem in that he
was using a 1-wire weather station and had difficulties recovering the
humidty value.  (some maths required on an A/D value I believe).
> I have subscribed to the OPNODE yahoo group as it looks as if it could
become very interesting...
>
> Nigel
>
The project is fairly mature now - and just works, and hence the list is
fairly quiet.  Daniel is very responsive in fixing things should you
find anything untoward .  I am very pleased with mine, inparticular the
aspect that the 1-wire reporting is totally standalone (embedded),
producing sensor readings to other xAP nodes and triggering 'actions'
without any PC dependency.

In my system I have strived for as much distributed operation as
possible so should any particular component fail it has minimal impact
on the rest of the system. Hence the sensors can drive the heating
demand direct or the behavior can be adapted by higher level algorithms
/ applications.  Indeed with fancier developments you can have
redundancy where another alternative device or controller can step in
should one fail.. still got that to work on.

OPNode  have also released OPNMax which is an embedded xAP controller.
Basically it utilises an NSLU2 'Slug' as the host and offers a SQLite
DB, graphing, logging, logic and scheduled xAP interactions web and ftp
as well as PHP and Perl scripting.   - all for the cost of the hardware
(circa £50).  Lots of little building blocks.    I do still use the
much
more capable HA software applications too.... for the more complex stuff.

K

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