[ha] Introductions.....

Hope & Mike Baptiste (mbaptiste.at.sprynet.com)
Thu, 03 Dec 1998 18:27:09 -0500

[Sent this a couple days ago but it never showed up on the list - so
I'll try again. Apologies if you get this twice. MB]

Just subscribed and figured I'd go ahead and introduce myself.

My name is Mike Baptiste. I live out in the North Carolina, USA in a
small town (~5000 people) I work in NC's Research Triangle Park for
NORTEL Network's R&D lab. While I'm a hardware type at heart, my 'real'
job is mostly software & systems work. So Home Automation is my outlet
for tinkering with hardware! My wife & I are planning a major remodel
to our house (~75 years old) so I have been busy planning the HA
'remodel' that will go along with it.

I've been actively working on my HA system for about 4 years now. It
consists of a few commercial parts and a few home built parts. It is
controlled by a Circuit Cellar HCS II controller board (
http://www.circuitcellar.com/hcs.html#SC ). I'm a big fan of embedded
controllers for HA and personally don't want to rely on a PC running
Windows to run my house. It crashes too much and seems like a waste of
processing power :) So the HCS allows me to write the control code and
download it into the controller. I also have CCI's PL-Link module for
X10 control (I hope to design my own X10 link at some point to add true
2-way monitoring of the new 2-way X10 Modules). The HCS II system is
ideal for home brew stuff since it uses a simple text based protocol the
runs over RS-485 to remote modules. It also supports daughterboards on
the controller for centralized functions like phone access and voice
synthesis. But the simple RS-485 network made it easy to build my own

I'm a big PIC fan and have built most of my HA interfaces with them. I
write my code in C mostly (assembler made my head hurt too much in
college :) ) So far I've designed 5 different HA interfaces for my
system and am working on a few more. They are:

Mini-DIO - Provides 8-bits of digital I/O anywhere on the RS-485 network
in a 16-pin package plus an 8-pin RS-485 chip
PIC-DIO - Same as the Mini-DIO but with a bigger packet buffer and extra
control lines for connection to a parallel printer. THus I can drop a
printer (or 2 or 3) off my RS-485 network I currently have a neat Seiko
thermal printer for logging system events, weather reports, etc.
PIC-LCD - A network LCD interface which supports multiple display sizes
up to 20x4, custom LCD characters, numerous ANSI & non-ANSI control
sequences, and beeper/backlight control.
Mini-Link - A tiny network interface used where you need a couple Analog
inputs or digital IO pins. It has 3 multi function pins (Analog in or
Digital IO) plus a 4th digital input. The entire network node is 1.8" x
X10_Relay - This board uses a PIC and an Allegro driver to control
between 4 and 16 relays which are turned on and off by X10 commands.
Thus you can control a bunch of low voltage devices without breaking the
bank for Universal Modules. Just finished this yesterday. When I saw
how much they wanted for a similar thing ($200-$300 for 16 relays) I
almost choked - so I built my own :)

I'm currently working on the PIC-LCD+ which adds 40x4 LCD support,
screen switching, and a keypad and also the PIC-TV which provides on
screen display capability for my system via a 3rd party video text
device (i.e. the chip is basically a protocol & control converter that
converts the HCS control command sinto commands the 3rd party text
device can understand)

You can see more details about my system at

and the custom modules at

The one project I'm messing with that is really neat is a lightning
sensor module which will monitor lightning strikes within a 100-250 mile
radius. Based on the frequency of hits, it can make decisions like is
the storm coming or going, how bad is it, and should my HA system start
shutting things down via networked disconnect boards for A/C, Coax, and
LV. It'll have a small LCD display plus a network port for my RS-485

The holy grail for my system will be some type of Internet interface.
Not to replace the RS-485 network but to provide an embedded web server
interface so I may control things via any web browser. Right now I have
to dial into my HCS directly and run a client on a PC if I'm not at my
basement 386 which is directly connected via RS-232. emWare
(www.emware.com) has some neat stuff where they embed a micro web server
in a PIC and then use Java and tags in a gateway to make the web server
appear full blown. Its a neat concept, but at $350 for a developers
kit, I might have to hold off for a bit. I'd also like to mess with the
wireless transceivers out there to try and build a wireless network node
for my HCS. I'm also toying with the idea of making an interface that
can handle up to 6 Dallas temp sensors and feed all their values back to
the controller via RS-485. This way the temp sensors can be far away
from the controller if necessary.

So while my system isn't completely home built, a lot of it is. So I
hope I can contribute ideas and such when it comes to embedded control
with PICs and such. I also have worked as an electrician's apprentice &
somewhat familiar with NEC codes so I might be able to help there too.

I tend to be a big believer in keeping it simple. I have to agree with
a previous poster that CeBUS is way to complex and thus costs way too
much. It has some good parts, but just like LonWorks, it costs too
much. My system currently has 7 network nodes running at 9600 baud.
The system polls each module for status changes. Yes, if you need
instant response to a digital input change, you won't get it since it
can take a second or two for it to register via a network poll. But the
controller has lots of digital IO locally that will provide instant
response. So by keeping it simple it allows me to construct
straightforward devices embedded in tiny PICs. One downside of RS-485
has always been it's 32 device limit. But Maxim has micropower drivers
now which allow up to 256 devices on an RS-485 network - with 15kV ESD

The only downside to the HCS in my opinion is that it is not an open
system. Thus, each module type is hardcoded (there are 6 or 7) But
each type packs a lot of data into its network query so I've been able
to mimic module types and get the data back to the HCS that I need.

So personally, I like an industrial network for HA, but it should carry
a protocol that is flexible enough to be used by any module you can
think up. Even better would be a setup where the controller queries the
network at startup to see what is out there and the modules reply back
with who they are and what packet format they will use so the controller
can auto configure. But I'm rambling.

It'll be interesting to see what develops here!

Mike Baptiste