My idea is a device "X10 like" but more powerful, wich can interface with
security system (alarm/dialer)
control electric appliances, input some data like temperature/motion
sensors/etc.
Speed is not a problem, since these devices could communicate each other in a
slow rate (very slow!)
The rs485 is a good choise, but need wire-wrapping around the house, and once
x10 work with relative
reliability, the power line comms seems to be an interesting point of "plug and
play"...
Phase problem can be solved with a single capacitor between the lines.
The price can be a factor of change to rs485, but i've seen some circuits with
an LM567 to decode
the FM signal, and the TX part with a few transistors.


> Hi all;
> I am also working on something similar and would be interested in setting a
> standard so devices could be inter-changed. My idea was to not use one type
> of physical bus but many with "routers" between them so that the most
> appropriate topology is used where it should.
> Can we talk about this off the pic list and kick some ideas about? Please
> email me direct.
>
> Lee McLaren
>
>
> I am also building a system to control some equipment in our house/office. I
> decided against the mains communication primarally beacuse of the problems
> with differnt phases and pricing and decided to go for 1-wire from Dallas
> Semiconductor. Cheap and rather easy to implement. Also to have a node where
> only switching, sensing of one/or to channels, temperature measurement can
> be implemented at a minimal cost without any type of controler at the node.
>
> By deciding on the 1-wire and wanting the nodes to be low cost I ended up
> with a master/slave concept where a PC is the heart of the system. This
> machine monitors all devices and take actions on certain sensor inputs. Also
> it implements a net interface so I can build a user i/f in the form of a web
> application. Thus its possible to check tempeartures at different locations,
> change the boiler temperature etc etc by just clicking around some web
> pages. Its also very easy to make changes in this user i/f when one needs to
> add/move a node in the system.
>

Silvio Borges
ssj@unorpnet.com.br
icq:2221034