The firmware for the ArduinoTrack has been developed within the Arduino.cc IDE. Since version 3.0, the firmware for the various use cases has been combined into a single package, and Precompiler Flags are used to determine the use scenario.
Determine the Mode of Operation
Single ArduinoTrack_Combined Shield
The most common use case is to run everything on the ArduinoTrack Shield, without a separate Arduino controller. To set up the firmware .ino file to run autonomously, find the #define's down around line 35 and be sure AT_COMBINED is defined, and any other definitions ("AT_MODEM" and "AT_FLEX") are commented out.
In the scenario of a single combined controller, you will still need an Arduino Uno (or similar) to program the Shield with the ArduinoTrack_Combined sketch. Once the Shield is programmed, you can disconnect the Uno from the shield and the shield will continue to function by itself.
Separate Arduino and ArduinoTrack_Modem
Alternatively, you can use the ArduinoTrack as an Arduino-compatible Shield, in which case the firmware on the shield is just responsible for acting as a KISS-compatable transmit only TNC. In this scenario you will need to download the alternate Arduino_Modem firmware .ino file to the shield (i.e. the KISS Modem).
After programming the Shield to function as a "Modem", download the main Arduino firmware should be installed to the Arduino host. To install that firmware, define the AT_MODEM compiler flag and load to the Arduino just like any other Sketch. Be sure that any other compiler flags such as "AT_COMBINED" and "AT_FLEX" are commented out.
Installing the Firmware
There are detailed steps to loading the firmware onto the ArduinoTrack Shield, found in the ArduinoTrack manual.
ArduinoTrack Manual - Section 8: Updating the Firmware
Latest Buids
All of these files are currently at version 3.1.2, designed for the ArduinoTrack Shield v1.11. The latest build can always be downloaded from the Custom Digital Services GitHub Repository, along with the hardware files.
The sketches have been tested and installed with the Arduino.cc version of Arduino v1.5.8-1.8.8.