Re: [LHA-misc] RE: HCS Web Pages

[Mike B. <bap...@cc...>]

Bob,

I was just about to reply to your email when I saw your post here.  I 
figured I reply here too.

First, the HCS itself is not $500.  The controller board sells for $299 
and includes the XPRESS HA software (more on that later)  $495 gets you 
teh controller, an 8 relay, 16 buffered input board, heavy duty metal 
enclosure, and an X-10 gateway/coprocessor board.

Yes, it uses and 'old' design, but not necessarily 'old' technology.  We 
upgraded the CPU used in the HCS-II, giving it a performance boost of 
2.5.  Not bad for an older design.  The key is, it still gets the job 
done with room to spare and it is a VERY stable and reliable platform. 
My telephone is based on 50 year old technology and still works as 
designed :)

I hope to add an Ethernet interface to the HCS-II using the Dallas TINI 
board Neil talked about earlier.  It will use web pages and Java applets 
to display system information and also allow you to control things.  It 
will allow the HCS to send email and can also FTP event logs from the 
HCS to servers or email them as well.

However, I have no plans to create a system that uses Ethernet as the 
core communications media.  The added expensive in hardware and overhead 
for the core processor are simply not worth it.  Plus Ethernet is NOT an 
ideal transport for 'control'  It is limited in distance (about 300'), 
requires 4 to 8 wires, and generally is not justified for things like 
controlling relays or reading analog values.  Someone may make a light 
switch with an Ethernet port, but it'll never succeed due to price and I 
doubt it'll pass code.  Now bluetooth or some other wireless varient 
might be a different story.  We'll see.

This is why RS-485 is so much better.  1 twisted pair can go 4000' and 
the tiniest processor can communicate with it.  So the ideal setup 
(IMHO) is a controller with Ethernet capability and RS-485 or wireless 
as the backend control network to talk with the end nodes used for 
control and monitoring.  That's why RS-485 is used almost exclusively 
for industrial and factory control.  It is easy to run, easy to wire, 
has excellent noise immunity and can approach speeds of 10MBps.

By having the main controller Ethernet capable, you can access your HA 
setup from anywhere, regardless of the backend network in use.  That's 
why I prefer and will stick with the 'gateway' concept for Ethernet at 
the controller.

As for the RS-485 hub, you don't 'need' it.  If you wire your modules in 
the proper 'daisy chain' fashion, its not required.  But many people 
like to wire their RS_485 devices in a star configuration which RS-485 
was not designed for.  But the RS-485 hub allows you to use stars in 
your RS-485 network.  That's another advantage of RS-485 in control, it 
is a multi-drop network that does not require the use of hubs like Ethernet.

Now, I agree that using an embedded Linux solution sounds appealing and 
it has advantages.  But don't mix apples and oranges.  The HCS-II is not 
just hardware.  It uses an advanced firmware program that provides for 
an easy to use control langauage called XPRESS (included in the $299 you 
pay for an HCS-II board)  You simply write a program to control your 
house, compile it, and upload it to the HCS-II.   There is 200 pages of 
code behind all that functionality.

Sure, you can use perl in Linux to control your house, but this means 
you have to worry about control AND the interfaces to the various I/O 
you might have.  Plus you have to write the low level drivers for things 
like X-10, analog conversions, timers, etc.  With the HCS-II (or other 
controllers like the Stargate, Ocelot, Magic Module, etc), you program 
at a higher level.  Its designed for folks that may not have in depth 
knowledge of C or perl or python, etc.

For example, to monitor a remote sensor and take action in XPRESS (or 
the language used in other HA controllers), you'd do something like:

IF Drivewaysensor = ON THEN
    FrontFloods = ON  ! X-10 modules
    FrontPorchLight = ON
END

With a Linux setup you talk about you'd have to write all the low level 
stuff.  Don't get me wrong, it can be done and many folks would enjoy 
doing it (myself included - a certified perl & Linux nut)  But realize 
that $300 for an HA controller is more than just hardware, regardless of 
the age.

Neil's project aims to provide a generic interface to the existing HA 
hardware (and any new stuff that comes out).  Its a great idea since it 
lets you take basic HA controllers and add even more intelligence to 
them.  But don't forget the above controller were designed as stand 
alone devices that don't require a PC to be on non stop.

Now regarding CeBus...  I personally wonder about its future.  It has 
been around for some time.  The parts and interfaces are VERY expensive, 
but that may change.  Microsoft has adopted CeBus which may give it 
life, but Microsoft is not a major palyer in home automation (yet)  I do 
know of one company getting ready to mass product light switches, 
outlets, etc based on CeBus.

The problem with CeBus is it requires a LOT of overhead.  Most of todays 
HA controllers are simple in that they use 8-bit or 16-bit embedded 
controllers which keeps thing ssimple (ie stable) and also keeps costs 
low.  I'll never forget an article I read in Circuit Cellar that 
outlined how to turn a RELAY on and off using CeBus.  It took up 5 pages 
and they provided no code, just high level outlines of objects and stuff 
that were very involved.

X-10 is popular with customers because it is inexpensive.  X-10 is 
popular with HA manufacturers because it is simple to implement.  CeBus 
is not and the chipsets are still really pricey.  CeBus is touted as a 
great thing because it is plug and play.  Who cares?  Do you REALLY need 
a light switch that auto sets itself?  Is it THAT hard to set an X-10 
address?

The second benefit I've heard is reliability.  Yes, X-10 has reliability 
issues.  But companies are working on improving X-10s problems.  The 
folks at ACT have come up with 'A-10' which is compatible with X-10, but 
it is MUCH more robust when it comes to powerline noise.  Yet it still 
uses the simple X-10 protocol.  But it also handles the extended data 
aspect of X-10 which until now has not been used due to the TW-523's 
limits.  Now there are new interfaces coming to market from ACT and 
SmartLinc which support extended codes.

So CeBus may take the HA industry by storm, but I doubt it.  But then 
maybe I'm just in denial. ;)

Sorry for the long post, just had a lot to cover and I haven't posted in 
a while! :)

Mike


Van Tassel, Bob wrote:

> Thanks Neil, that was very helpful.  I'm now thinking along the lines of
> buying a board from Lineo for $300 that has Linux and Ethernet already on
> board with 21 I/O pins.  Check them out
> http://www.lineo.com/products/ucsimm/index.html.
> 
> I realize there is a lot of support and info for the HCS board, but the
> hardware is using five year old technology and costs $500.  Seems like all
> that is missing from the lineo solution is an XJ11 connector to talk to a
> Two-way Powerline Interface (TW523) from X10.com.  Am I missing something?
> 
> I'm starting from a clean slate, so I'm trying not to just blindly follow
> what most people are doing.  Which is why I'm thinking about CeBus.  Are
> X-10 commands simply a subset of CeBus?  Do you know of a TW523 like device
> for the CeBus?
> 
> Thanks again, Bob.
> 
> -----Original Message-----
> From: Neil Cherry [mailto:nc...@ho...]
> Sent: Wednesday, November 22, 2000 10:56 AM
> To: Van Tassel, Bob
> Cc: Wedekind, Jeffrey; Nguyen, Hai; Fleming, Kevin; LHA-misc
> Subject: Re: HCS Web Pages
> 
> 
> 
>> "Van Tassel, Bob" wrote:
>> 
>> http://members.home.net/ncherry/common/hcs/index.html
>> 
>> Great site!  I realize that the HCS-II is made from an old Circuit Cellar
>> design, but are there plans to upgrade this puppy with an Ethernet
>> controller?  I think it sucks big time to have to buy an RS-485 hub for
> 
> $139
> 
>> to do networking, when Linux is so rich with a built in TCP stack.  Does
> 
> your
> 
>> code use PPP over the RS-485 bus?  I'd like to be able to use a HA system
> 
> from
> 
>> any computer in the house.
>> 
>> Thanks, Bob.
> 
> 
> I've included everyone, I hope you don't mind. The HCS II will probably
> not get an ethernet controller. But it is possible to hook up a Dallas
> Tini board to the ether' and the serial port the HCS II so that can
> provide an ethernet interface. The Dallas software would be written in
> Java, there is code to allow a CM11A to Dallas to ethernet. This should
> hackable to permit other devices to communicate between the serial and
> ether.
> 
> Having said all that, there is also plans for an HCS III and that may
> have an ethernet as it's based on the EZ80 by Zilog and Rabbit Semi.
> They have a version with an ethernet and since the HCS II is based on
> the Z80/180/S180 it seems like a logical path. Check out:
> 
> http://www.cc-concepts.com/opensource/
> 
> Now onto your other questions. There is no need for an RS485 hub you
> can simply string (daisy chain) them up to each other (a star config
> requires a hub). The total max devices: 32, the total length of cable:
> 4000 feet.
> 
> My HCSd code has the HCS II directly connected to the serial port (no
> TCP/IP or ppp, just straight 8 bit ASCII [0-255]) but it allows you to
> telnet from anywhere on the network to the port (assuming you have the
> routing working if it's a big network like the internet).  The telnet
> session is standard 7 bit ASCII, commands are "!12000200" (literally
> you type everything between the double quotes). That command is Set
> X10 A1 on. It will respond back with "$12" saying that it exec'd the
> command. I also wrote a perl program which runs under Linux and W95 to
> download the program to the HCS. Other commands will also be written
> in perl (for proof of concept) to turn things on, off, get status,
> what ever is appropriate. Multiple computers can attach to HCSd at the
> same time. I make no attempts to keep 2 users from issue dueling
> commands. There is also no security (I have TCPD compiled in by
> default, but that's not security). I expect security to be handled via
> outside programs, SSH, IPFilters, Net filters, IP table, etc. Here's
> an ASCII picture:
> 
>                          +-------+
>                          | Other |
>                          +---+---+
>            Ethernet          |
>  ]----------+-------SS-------+---------[
>             |
>      +------+----+
>      | Linux Box |---------> Internet Access (PPP/Slip/Cable/DSL/ISDN/AX25)
>      +----+------+
>           |
>           | RS232 Serial port
>           |
>        +--+--+
>        | HCS |------> RS485 network
>        +-----|
>         | | |
>         O O O (Digital/Analog I/O)
> 
> In the above diagram (fix font), SS means that those 2 parts of the
> network may not be on the same net. If not, they'll depend on normal
> TCP/IP routing. Technically they could be across the internet. There
> doesn't have to be a network card either, just as long as the
> interface looopback or dummy network is up. This will allow people
> with just a serial dial up to use the program. The daemon depends on
> TCP/IP doing it's thing correctly. The picture doesn't include a
> firewall but if you try to access from outside the safety of your home
> I recommend a seperate firewall box. I know this isn't practicle for
> dial up users, I still recommend using a firewall! The "Other" box can
> be anything, DOS, WinX, a MAC, another *nix box, a Dallas TINI board
> with keyboard and LCD (or just touch screen), or even CP/M. :-)
> 
> I hope that answers your questions.
> 
> BTW: You won't be able to post directly to the LHA project list, it will
> be sent to me and I'll have to approve it. Only members of the list are
> permitted to post to the list because of SPAM problems.


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Creative Control Concepts     http://www.cc-concepts.com/
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