There no doubt that houses are getting "smarter" all the time. More and
more new homes are coming with goodies like alarm systems, intelligent
controls for HVAC, pools and sprinklers and even devices to monitor power
consumption in real time.
I've seen a lot of very expensive and complex systems to manage the
functions of "smart homes" but I've never come across something as small,
powerful and inexpensive as this unit:
I've cross-posted this in comp.home.automation and alt.home.repair because
I've seen a lot of posts about monitoring house conditions like temperature
remotely in both groups. I was first alerted to the product in a thread
about USB home control in CHA. In that thread:
_USB module for monitoring multiple on/off switches_
Marc Hult recommended this device instead as a much more practical way to
"communicate" with your house remotely than USB devices connected to a PC.
It took me a while to find the secret URL and I don't give cainetworks an A+
for website design - this product doesn't even show up on their "Product
List." They seem to be a server load balancing company and I would guess
they built this thing for themselves as a service tool and then began to
realize it had other applications.
I have no interest in the company, other than as a customer and it's too
early to tell whether I am a happy customer or not!
WebControl interests me for a number of reasons: it can automagically send
emails to a PC or a cell phone when a looked-for condition occurs, assuming
you've got a constant internet connection. This condition could be a
furnace failure, an out-of-bounds temperature, water on the floor or any
number of other events that can sensed electronically.
It's got plenty of inputs - it can accommodate a Honeywell humidity sensor,
up to eight Maxim DS1822 /DS18B20 12bit 1 wire temperature sensors, eight
digital inputs, three analog inputs and 20 different timers. It seems from
my Google searches that these are popular with cigar lovers (to keep their
treasures at constant temps and humidity) and in-home horticulturists
growing various "herbs."
My first project will be a sensing project, too: I'm hoping to use it to
continually monitor how much power the whole house uses in real-time. I've
read about a number of test projects using "smart meters" and they all
pretty much say the same thing: People who know how much power they are
using at any one moment will end up reducing their average monthly
I've got some tiny current sensors that I will attach to the main power
feeds to the circuit panel, hopefully so artfully that an inspector might
never notice they're there. (Yes, I know the evils of mixing high and low
voltage gear and I don't recommend anyone but an insane person with total
contempt for life and the law even contemplate copying my actions!)
These tiny (1/4" sq.) Hall-Effect (HE) sensors generate a small electric
current proportional (well, proportional enough for me) to the current
flowing into the house from the main feeders. This unit should enable me to
see the current current use from any PC on the home network. I should even
be able to rig up an LED bargraph display that shows the real-time power
consumption of the house with another $2 worth of parts.
The unit has three 3 1023 bit analog inputs (0-10v) that should be able to
accurately measure the HE sensor voltage level and take an action (light a
bargraph LED, ring a chime, etc) when the voltage becomes greater than a
pre-determined level. Perhaps the hardest part is going to be accurately
matching the output level of the sensor to the actual home electrical power
consumed. If I can't get a helper with a walkie talkie, I can temporarily
mount a wireless CCTV cam outside pointing at the electric meter so I can
tabulate meter readings and how they correspond to the sensor output as I
add more and more loads. I will start with all the breakers off, but with
lights, etc. left on so that as I flip each breaker on, the load increases.
That way I should have a scale that gives me a pretty good idea of the juice
flowing through the circuit panel.
I'm going to make notes as I go along, paying particular attention to the
level of technical skill required to implement it. I'm afraid it's going to
be high enough to make it a techie-only solution. But looking through the
gives me at least a little hope that this unit may be simple enough that
with a little advice, a fairly low-tech user could implement a simple system
that could, for example, send them an email if their freezer or refrigerator
temperature rises out of the food safety zone. Ironically, that's why I
ordered the board (my fridge tripped the GFCI) but once I read the manual
and the specs, I realized it would probably make a good and cheap whole
house power monitor.
Previously, devices like this cost close to $200, so to my mind it's a great
The part that I haven't quite figured out about whole house power monitoring
is this: What's the best way to notify residents that the house is burning
kilowatts without being so intrusive that they'll just shut it off? There
has to be some sort of override, too, because there will be some days in the
dead of a very cold winter that the consumption will peak.