Mossel Bay WX Projects: APRS Search and Rescue Tracker (Photos and Information)

The Search and Rescue Tracker is based on the Automatic Packet Reporting System (APRS) for real time tactical digital communications of information of immediate value in the local area of the Southern Cape. In addition, all such data is ingested into the APRS Internet System (APRS-IS) and distributed globally for ubiquitous and immediate access. This tracker is not only used for Search and Rescue purposes but also for general amateur radio-, High Altitude Balloon Tracking-, Digipeating-,Announcements-, Bulletin-, Message-, Alert-, Weather and Disaster purposes and of course a map that reflect objects, satellites, emergency nets, Search & Rescue Objects and  Search & Rescue Logging ect.

For more information on the current network running in the Southern Cape area click HERE. 
Let's move on to the tracker build. There is several tracker units on the market that can be used.  I played around with several units in the past.  This time around I decided to use a Arduino/PCB Tracker which use a Trackuino open-source sketch.  I am not going to go into great detail here as there are literally hundreds of websites that contain an abundance of information on how to build this tracker.  The unit I constructed contained the following features:

• Arduino shield form factor (you can stack more shields on it)
• GPS: Ublox LEA-4P Module. (RF Design)
• Radio: Baofeng UV-5R VHF/UHF HT
• 1200 bauds AFSK using 8-bit PWM
• Sends out standard APRS position messages (latitude, longitude, altitude, course, speed and time).
• Internal/external temperature sensors (LM35) to read temperature in and outside. (To still be activated.)
• Active/passive buzzer support to ease acoustic tracker location.(To still be activated.)
• Trackuino intervalometer (To still be activated.)
• Open source (GPLv2 license), both software and hardware. In other words, you can do whatever you want with it: modify it, add it to your project, etc. 

An Arduino Uno board is used for the "brain" of the Tracker. I  build the radio interface unit on a small piece of  Veroboard.  The GPS connections were made and the sketch were uploaded to the Arduino but dear o dear nothing happened.  No GPS data nor APRS packets were seen or heard. After a few component changes and modifications the tracker came to life with AX25 packets.  Yeah it is working but will the signal be decoded by packet modems.  Sadly no decoding.  Some more fiddling around and wa-la I can now decode the packets with my PK232 Modem.  Finally the tracker is working, however I am still experimenting with some of the features.  I now have a fully functional APRS Tracker which is way cheaper than any of the commercial and other amateur radio units currently available.

The following images show the different modules of the tracker:

Photo1:  Arduino Uno Board

Photo 2:  Radio Interface Board (Veroboard)

Photo 3:  GPS Ublox LEA-4P Module

Photo 4:  5v Power Supply Module

Photo 5:  GPS + Arduino + Transmitter Module

Photo 6:  Baofeng UV-5R VHF/UHF HT

I will update this topic with more images and reviews of the unit once I am finished with experimenting.  Stay tuned and read what this tracker can do and how it can be used for Search and Rescue and other purposes.

- MSBWX