Timothy Weber wrote:

> Yes, I'd seen it before - looks very nice!

thank you :)

> This at least illustrates my point - which I think is that anyone 
> dabbling with home automation, and perhaps even serious industrial 
> automation developers, eventually needs/wants some kind of 
> infrastructure like this.

I have seen this actually done or at least "proposed" by some big firms 
around. Looks like people took some time :) but then this way of 
thinking got spread - as the the more efficient. Personally, I'd say 
that I was considering Ethernet as the medium of the future (for home 
automation, but take it as car-automation too) back in 1997... but, 
later, I saw that, smaller, more efficient (and less power/resources 
hungry) protocols could act perfectly down there. But, then, you had to 
interface those protocols to other standards and so...

And, even in 2008, having a "home automation" node, say a dimmer, with a 
Ethernet I/F would be, IMO, a waste of space, power, and complexity.

"Scalability" is probably the right word.

> And I'm thinking that having something generic and portable, with some 
> of the project-specific idiosyncrasies yours and mine undoubtedly have 
> smoothed off, might be useful even for small one- or two-node projects 
> that need convenient access to node data from a workstation.

Yes, true.
Maybe that some "tailoring" will always be needed, i.e. it can be 
somewhat easy to embed a 485 packet (or, for that matters, a X10 frame 
or a Zigbee frame) into a UDP datagram... but requesting a value from a 
Meteo-Station via a HTTP query is less-likely to be standard. Or maybe 
it's just because no one has standardized it yet!



> Did you find any other options out there worth considering before 
> rolling your own?

Hmmm, I started this home automation thing in 1992, developing some 
Z80-based boards with expansion daughter boards, with I/O @24, 220V and 
such. Then tried Power-line modems (ST7537 from ST and TDA5050...1 from 
Philips) but they were not very good, at least to me. So I started using 
PICs in 2001 and then chose to use RS485: I started out @9600 baud, then 
moved 19200, then 57600 and now 115200.
Writing my own protocol was mostly... fun! But then, you learn a lot 
from your errors and looking at other people's work - for instance, I 
got the "repeated frame" thing attending a Nordic meeting.


> (I've generally discounted X10 and similar as too proprietary and 
> expensive to invest in, especially for someone capable of working with 
> PICs.)

yes, in fact.
Actually they were also hard to find in Italy, at least back in the 90s 
(where are you located by the way?)


-- 
Ciao, Dario -- ADPM Synthesis sas -- http://www.adpm.tk
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