pic microcontroller discussion list <> wrote on Thursday, June 05, 2003
10:30 AM:

> mind, meaning that all electrical systems would be able to be wired
> up. I have been investigating all the different systems, and I must
> agree that X-10 is way out there.

For a new build, wired is _definitely_ the way to go.  Why battle with the
weaknesses of mains-borne X-10 (missed commands, extra commands) when you
can run an extra cable and fit a relay or dimmer module for less cost?  I
have several X-10 modules, a timer and RF controller among them, and they
are useful for short term changes, but I wouldn't trust them with anything
remotely important.
The RF receiver switches its built in relay on and off when it feels like
it (must be a glitch on the local switch sense), and sometimes it and
another module on the same house and module code switch on 'because they
feel like it' (so they have 'seen' a non-existent X-10 command).  Sometimes
the RF receiver 'crashes' and needs a power cycle to start responding to
commands again.  That's OK (almost!) because they are just controlling
lamps, but I like to be able to control central heating etc. as well!

> lot of the other systems. Please note that I am not trashing X-10.

I am not either, but if you can run cables instead, that will _always_ be a
superior solution.  Only the cost or inconvenience of running cables can be
a reason to use X-10, and if it's a new build that should be insignificant.

> I have currently got a system that I made which is working fine, but
> the problem is that is a parallel bus system. So all the connected
> items have to be wired back to the control system. Where a serial
> system can have controllers all over the place and devices just wired
> to the closest controller.

Have a look at http://www.ibutton.com .  I am using more of that now,
especially for temperature measurements, it's reliable (and should soon be
controlling my central heating), and only needs a single 2-wire bus, but
avoids the complications of building CAN controllers.  Cheap too...

> All of this taken into account, and what I have seen from looking
> around, HA will most probably be a combination of a stack of
> different Technologies.

Yes, definitely.  I have one row of Krone terminals for each 'technology',
and currently have space for 20 rows, with 15 allocated ... why fight
phone, audio, video, security etc onto one protocol when you can spend a
couple of euros and run another length of cable?

Nigel
--
Nigel Orr, Design Engineer                 nigel@axoninstruments.co.uk
Axon Instruments Ltd., Wardes Road,Inverurie,Aberdeenshire,UK,AB51 3TT
               Tel:+44 1467 622332 Fax:+44 1467 625235
                   http://www.axoninstruments.co.uk

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