Overview

This is an APRS tracker for the Arduino/Atmega328p platform. It gathers position data from a GPS and broadcasts it via radio using standard APRS position messages. It was designed primarily to track high altitude balloons, so it has other handy features like reading temperature sensors and a cut-down mechanism.

Trackuino is intended to be used by licensed radio amateurs. By operating on the standard APRS frequency, the signal can be picked up by an Internet gateway and reported on aprs.fi, so anyone with an Internet connection can track the flight live and even help with the chase!

The project comprises both the firmware and the schematics/PCB to build your own stand-alone tracker. The tracker board includes the microcontroller, the GPS module and the radio transmitter. You can also run the firmware on an Arduino and wire up the GPS and radio modules externally.

This is how a finished board looks like:

Main features

GPS: Venus 634FLPx. Reports okay above 18 Km.
Radio: The board supports Radiometrix's HX1 (300 mW) as well as Argentdata's MX146-8v (500 mw).
1200 bauds AFSK using 8-bit PWM
Sends out standard APRS position messages (latitude, longitude, altitude, course, speed and time).
Internal/external temperature sensors (LM60) to read temperature in and outside the payload
Support for 1 capacitive humidity sensor
Cut-down aka "suicide" mechanism: you can hook up a nicrom wire and cut the payload line if your balloon gets stuck aloft for a long time.
ICSP header for in-circuit programming
2 x SMA female plugs (1 x GPS in + 1 x radio out)
Open source (GPLv2 license), both software and hardware. In other words, do whatever you want with it: modify it, add it to your project, etc. as long as you opensource your modifications as well.

How to build your own

Both the schematic and PCB Eagle files are in the downloads section. You can do the exposure/development/etching process yourself, but I suggest sending it to a PCB house. I made the project public at BatchPCB, so anyone can go and order one.

The Trackuino is designed to work with two different radios: Radiometrix HX1 and Argentdata MX146 8v. I suggest you build the HX1 version, since it's cheaper and it involves less components.

Here is the bill of materials:

For the HX1 version.
And for the MX146 version.

Downloads

Get the latest stable release from:

http://code.google.com/p/trackuino/downloads/list

or use a svn client to get the latest snapshot:

svn checkout http://trackuino.googlecode.com/svn/trunk/ trackuino-read-only

How to compile

The easiest way is with the Arduino IDE. Download the latest "trackuino-ide-xxxxxxxx.zip" from the downloads area. Unzip it in your sketches directory.

Now, you have to change some settings. Go to the "config.h" tab and:

Put your own callsign and SSID here. By default it's nonsense, something like "MYCALL-11". SSID 11 is good for balloons.
Select your type of radio here (HX1 or MX146)
Optionally, add some custom comment to the APRS messages, set a different TXDELAY, change the APRS update period (default = 61 seconds), etc.

Next, compile and flash your Arduino. Then, you can take the AVR chip from the Arduino and put in your Trackuino board.

If you're comfortable with command line tools, there is also a "trackuino-gcc-xxxxxxxx.tgz" version with Makefiles that you can compile with the gcc-avr toolchain on Linux and Mac OS X.

Support

Discuss firmware bugs, suggestions or ask for help at the hab-ham.org forum.

More information

For the nitty-gritty, check out the wiki.

You can also follow us and stay up-to-date at the project's blog: