●●●●
When I first started this
series, I knew I wanted
to build a wireless
weather station. In no
way could I have
imagined how well
the overall system would
function, nor could I have
envisioned its versatility.
CONTROL
YOUR WORLD
Build a Wireless Weather System: Part 1
In this article, it all
comes together.
The wired 1Wire network has
five main disadvantages:
5) If lightning strikes your weather
pole, you run the chance of blowing
up your computer or display system.
If you have already built
a PC or microcontroller-based weather station
connected to a 1Wire
network, you may be
asking yourself why you
should go to all the effort
and expense of converting
it to wireless.
1) Your system is tethered and you
have to run a cable to the location
where you want to place the
display. This can be problematic and
time consuming.
2) You are limited to the length
of the cable and the number of
items you can reliably place on
the cable.
3) If you want to add additional
sensors to various locations, this can
prove almost impossible if you don’t
have access to attic or basement
areas.
4) With a wired system,
you generally only have
a single display system.
■ FIGURE 1
With a wireless system, all these
problems will be solved. The only
cable that needs to be run is for a
power source. This is simply two
wires and in many cases can be a
very short run. You can even power
your weather pole with a set of solar
cells and a rechargeable battery.
The heart of our wireless system
is a Zigbee mesh network. You have
probably read about mesh
networks, but this is your chance to
actually build one and put it to
work. Once the network is built, you
will be able to add sensors or displays to any location in your home.
In addition, we are going to add
extra features like the ability to
create as many display systems as
we like without
having to change
the network in any
way. For instance,
I can add a PC
interface to the
system by simply
■ FIGURE
2 adding a Zigbee
unit to an RS-232
card and I can start
collecting data. At
the same time, I can
build a small LCD
display for my
desktop. I can add
a large LED sign
display to the front
entrance of my lab
NOTE:
The parts list for this project will be
included in Part 2 next month.
46
September 2007