Experiments with
Alternative Energy
Part 12 - Build the Telematics Car
By John Gavlik, WA6ZOK
Telematics is the twenty-first century word
for “telemetry” which was coined somewhere
around the mid-1950s, to mean wirelessly
transmitting data from one point to another
— usually from a moving vehicle like a car,
plane, or spacecraft to a ground station.
These days, telematics is an entire industry
generally focused on modern automobiles
that wish to be “always connected” to where
they are and where they are going. GM’s
OnStar™ is one example, as is FordSYNC™
that purport to keep you in touch with your
vehicle as you drive — as well as the
environment in which you’re driving — with
things like GPS voice activation, accident
detection, directions to the next filling
station or restaurant, etc.
Figure 1. The
Telematics Car.
So, what does any of this have
to do with fuel cells? The answer is
that we are about to equip our
[already spectacular] fuel cell
powered Hydrocar with telematics
capabilities. That is, we will equip it
so that it wirelessly transmits the
Hydrocar’s electric motor parameters
to your computer as it moves; this
will include [the measure of] the
voltage, current, motor resistance,
and power wirelessly transmitted in
real time to your computer. That way,
you can see exactly how the car’s
motor and fuel cell react when it
starts, stops, moves forward, reverse,
and up hills and down. Our
telematics circuitry will transform a
toy into an intelligent teaching tool
(Figure 1).
ZigBee® and XBEE®
To do this, we will employ a
relatively new and powerful wireless
technology called ZigBee (formally
known as IEEE 802.15.4) that does
the hard work of taking in RS-232
type serial data in one module
mounted on the car and wirelessly
sending it to a receiving module
connected to your computer — all
without interference and special
protocols that are the norm with
standard RF methods (like some of
the popular 400 MHz and 900 MHz
radios). To make matters even better,
companies like Digi International
(formally Maxstream) have created
plug-in modules they call XBEE that
contain the ZigBee circuitry plus an
antenna. Just add + 3. 3 volts and a
connection to the RS-232 source and
you’re in business (see sidebar).
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July 2010