Telementery Ideas

[Frederic Breitwieser]

>Telemetry data logging is not very expensive xcevers pair~$100 2 watt
>amp ~$75  . Transfer rate 40kbs . To do bi directional half duplex (both
>can't talk on the air at the sametime)add $75 for a second amp also
>needs switch electronics . Find a ham club they may have some experts on
>digital rf in the group (don't use a tnc (ham modem)they will suggest it
>) it is slow ,expensive, bigger and uses much more power than the parts
>I'm using.

HAM radio is certainly one good solution for this need.  I've taken it a
step further, and starting to build my own circuit.

For the RF components, I ordered a paired RF system from
www.linxtechnologies.com, which convert serial data directly to RF, then
unconvert them on the other end.  They have three sets of modules, and for
experimentation, I went with the cheapest system possible, but it only
supports 9600 baud on a good day.  Ideally, I'd like to use the more
expensive 900MHZ version, which can take 56KB, and will do so in the final
release.

To pass the data to and from the circuits, one can utilizing a PC's serial
port, or an embedded processor's par to serial interface chip, either built
in or external, depending on your configuration.

This circuit started out as a two way data communications link for a
different project (go to www.robotwars.com), but once its completed, I will
be incorporating the 900mhz version into my mid-engined vehicle for data
logging.  Though laptops aren't all that heavy, I must admit, and could be
strapped into the car without any real disadvantage.


Frederic Breitwieser
Bridgeport, CT 06606

Homebrew Automotive Website:
http://www.xephic.dynip.com/

1993 Supercharged Lincoln Continental
1989 HMMWV
2000 Buick-Powered Mid-Engined Sports Car