Timewave DSP-232, Operating Manual

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Chapter 6 GPS Applications
Chapter 6
Global Positioning System Applications
Overview
This chapter describes how to configure and connect your TNC for GPS operation.
Why do GPS in the DSP-232?
All AEA TNCs can run with Automatic Packet Reporting System (APRS) software. The DSP-232, however, has
special firmware which makes Stand Alone Tracking, remote GPS command programming, and Ultimeter II
compatibility possible. With the DSP-232, you can use VHF or HF packet for position transmission. AEA also
offers an APRS Adapter Cable for the DSP which makes Hardware Single Port Mode (HSP) operation possible.
The DSP-232 contains special GPS features not found in other packet data controllers. The DSP-232 can detect
whether or not a GPS receiver is connected with the
GPSAuto command, it then chooses the appropriate
GPSMode of operation. If a GPS receiver is detected upon power-up the DSP-232 automatically sends a GPS
initialization string. The DSP-232 can be remotely polled by addressing a packet to its GPOLLCall , or by the
polling features in APRS. The DSP-232’s GPS commands can be remotely programmed using the GREMprog
command which is very convenient in Stand Alone Tracking applications—the unit never needs to be taken out of
the vehicle to change GPS settings. GPS receivers can be remotely programmed via the DSP-232. The DSP-232’s
internal time and date can be set from the information obtained from the GPS receiver. There are provisions for an
external input to cause the sending of NMEA strings, such as from a radio control head button. The DSP-232 can
even operate packet and GPS at the same time using the commercial mode.
What is APRS?
Automatic Packet Reporting System (APRS) is a
copyrighted software program developed by Bob
Bruninga (WB4APR) which is distributed as
shareware for real-time Packet communications. The
software keeps lists of stations heard and displays
the locations of stations visually on a computerized
map like the one in figure 6-1. The maps can be
scaled from .5 to 2000 miles. Few of the maps are
complete, however there are tracking features built
into APRS which allow you to create maps just by
driving down the streets of your town. Amateur
operators all over the country are creating maps
which can be downloaded from on-line systems for
use by all. Stations can appear on the maps and each
station may be given a symbol such as a house, car, or boat. The real benefit of using APRS software is in mobile
tracking applications. Vehicles and people can be tracked and mapped using APRS. APRS also includes the ability
September, 05 6-1