There is new APRS tracker founded on indyTracker official site.
With only one Arduino pro mini and GPS module you can create APRS tracker.
Here is schema

To load configuration, connect USB-TTL adapter to Rx and Tx pin on Arduino, and open terminal program. You can use putty
Select appropriate COM port and choose 9600 speed rate.
Command ?disp
for list setup.
For writing new data use following construction ?wa?callsign-9
where
?w
command for saving
a?
variable to save
callsign-9
string to save
Existing variables are:
a_MYCALL
b_Symbol_1
c_Symbol_2
d_PATH_1
e_PATH_2
f_FastSpeed
g_FastRate
h_SlowSpeed
i_SlowRate
j_GPS
k_TrackerMode
l_MyBeacon
Example of good configuration:
a_MYCALL callsing-8
b_Symbol_1 />RUN
c_Symbol_2 \PSTOP
d_PATH_1 WIDE1-1
e_PATH_2 WIDE2-1
f_FastSpeed 70
g_FastRate 45
h_SlowSpeed 1
i_SlowRate 600
j_GPS 9600
k_TrackerMode 1
l_MyBeacon
Best way to save you config is to prepare you config in Notepad and then paste line by line to Putty.
Here is example of config from Notepad
?wa?callsign-8
?wb?/>RUN
?wc?\PSTOP
?wd?WIDE1-1
?we?WIDE2-1
?wf?70
?wg?45
?wh?1
?wi?600
?wj?9600
?wk?1
?wl?MyBeacon
PIN 3 = PTT+
PIN 4 = PTT-
PIN 5 = PWM AFSK out
Rx = GPS 9600
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