Trackuino 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. 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.