What is APRS?

This is my completed T4 Tracker project.
TinyTrak 3 TT3 + Delorme TripMate = T4

Completed 1-3-2004

My T4 project was to turn a Delorme TripMate GPS
into a dedicated mobile tracker, but to still be
able to plot my location on a laptop. I also
wanted to be able to run the GPS off of the 13.5
volt power in a vehicle. The first step of the
project envolved modifying the Delorme TripMate to
startup automatically. The TripMate outputs a
message "ASTRAL" upon start up, and will not start
outputing NMEA sentences until it hears "ASTRAL"
from a laptop. This is easy to modify by connecting
the serial data out to the serial data in,
thus making the TripMate answer itself.

TripMate wiring before modification

Cut the brown and red wires at the solder pad.
Create a solder bridge between the solder pads for
the black and brown wire. Solder the red wire to
solder pad above the yellow wire.

Next step was to add a 7805 linear voltage regulator.
This allows the TripMate to run on 5-35 volts. This
of course includes the 12- 13.5 volts from a car
cigarette lighter.

-I'll add more information here soon.

Next step was to build and integrate a TinyTrak 3.

Completed TinyTrak 3

The TinyTrak 3 is very simple to build. It took me
about an hour to build it, and another hour to modify
the TripMate case (I added a DB9 for direct connection
to a 2 Meter radio.) and integrate the TinyTrak to work
with data from the TripMate, and to build the cable for
the TinyTrak to interface with the radio.
After great thought, I decided to go ahead and use
the DB9 connectors on the TinyTrak 3. I had enough
room to put them on and it would allow me to remove the
TinyTrak 3 from the TripMate, and use it in my truck
as a spare if my other TinyTrak 3 ever decides to quit
working. That way I can fix my other TinyTrack 3 at my
I can also receive data on the original TripMate serial cable
thus allowing me to use the TripMate like "normal."

Below are various pictures of the completed project.

TinyTrak 3 Receiving a GPS Signal -Green LED

Project, being tested.

TinyTrak 3 & Delorme TripMate

Completed, and ready to use

My new soldering iron.

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