Wireless connections are everywhere. When I walk
into a restaurant and everyone has a device in
their ear, I sometimes wonder if I missed the alien
attack. The
wireless technology known as Bluetooth is the fuel for
this invasion
The 30 foot range and relatively low power
requirements make Bluetooth well suited to replace
cords in consumer applications. Besides headsets
Bluetooth connects:
- GPS receivers
- Heart rate monitors
- Stereo headphones and speakers
- Mice (computer that is)
ZigBee is Bluetooth's industrial sibling. It is designed
to be very low power. The devices "sleep" when not in
use and batteries may last 5 to 10 years. ZigBee also
supports thousands of networked devices versus
Bluetooth's 7 devices.
The tradeoff with ZigBee is the smaller amount of data
that can be sent. ZigBee also responds quicker than
Bluetooth, making it ideal for sensor applications or
simple control. A ZigBee connection is not going to
transmit your voice, but it could tell you the
temperature on the roof without running a wire up
there.
Another real life application could be adding a
switched light in an existing room. Normally you
would cut a couple of holes and try to fish wires from
the switch to the light. With ZigBee you could just
power the light and glue the switch to the wall.
ZigBee really shines in an application that has many,
widely dispersed points that need to be monitored. A
large group of tanks (think oil refinery or wastewater
treatment plant) that each have level and temperature
sensors, pumps, and valves would be perfect for
ZigBee.
Both of these technologies help eliminate wires.
Bluetooth is primarily driven by convenience. The wire
gets in the way. ZigBee can be a technology that
helps reduce cost. Especially with the price of copper
and installation labor, it can be expensive to run wires
all over a plant. In the
end the success or failure of ZigBee will probably
come
down to economics.
