How to make Open GPS Tracker System

The Open GPS Tracker is a small device which plugs into a $20 prepaid mobile phone to make a GPS tracker. The Tracker responds to text message commands, detects motion, and sends you its exact position, ready for Google Maps or your mapping software. The Tracker firmware is open source and user-customizable.

We currently have second-generation stable firmware and a reference hardware design. All parts are available from Mouser Electronics, and the phone is available from Target, Walmart, or Radio Shack. This site provides the firmware with source code, theory of operation, parts list, and exact assembly and checkout instructions. If you can solder, this is a one-sitting project. No PC board or surface-mount capability is required.

Programmed parts will be available as soon as the firmware is out of beta. We intend to have kits and assembled units available for purchase shortly thereafter. Commercial products are planned, but the firmware will remain open source.

The current supported hardware platform is:
• Tyco Electronics A1035D GPS module
• Motorola C168i AT&T GoPhone prepaid mobile phone
• Atmel ATTINY84-20PU AVR microcontroller
We intend to support more phones and GPS devices in the future.
The Tracker's features are competitive with, or better than, many commercial products:
• SiRFstar III receiver gets a fix inside most buildings.
• Sends latitude, longitude, altitude, speed, course, date, and time.
• Sends to any SMS-capable mobile phone, or any email address.
• Battery life up to 14 days, limited by mobile phone. Longer life possible with external batteries.
• GoPhone costs $10 per month for 1000 messages per month.
• Configurable over-the-air via text message commands.
• Password security and unique identifier.
• Manual locate and automatic tracking modes controlled via text message.
• Automatic tracking mode sends location when the tracker starts moving,
when it stops moving, and at programmable intervals while moving.
• Alerts when user-set speed limit is exceeded.
• Retains tracking messages if out of coverage, and sends when back in coverage.
• Retains and reports last good fix if it loses GPS coverage.
• Remote reporting of mobile phone battery and signal status.
• Extended runtime mode switches phone on and off to save battery life.
• Watchdog timer prevents device lockup.
• Firmware is user-customizable with a $35.91 programmer and free software.
In addition to being a GPS tracker, the firmware is easily modified to monitor and control anything from a weather station to a vending machine via text messaging.

For More Details: 
How To Build
Command
Download Source Codes and Circuit Diagrams
How To Customize