After startup, the program (main.py) is launched immediately. Upon launch, gps-tracker communicates with the GPS daemon (GPSd), which manages the connection between our program and the GPS antenna by providing an interface which gps-tracker can consume). Through this interface provided by GPSd, our program can have access to a steady stream of 2 dimensional coordinates (latitude and longitude), which is then passed to Ubidots for the construction of a map that can be used to determine the location of the tracker.
