text: /*
   * Global functions
   */
  
  void init_analog_io(void);          // Setup the analog hardware
  unsigned int read_reference(void);  // Read the feedback channel
  void show_analog(void);             // Display the analog values
  void cal_analog(void);              // Calibrate the analog threshold
  
  /*
   *  Port Definitions
   */
  
  #define NORTH_ANA    1          // North Analog Input
  #define EAST_ANA     2          // East Analog Input
  #define SOUTH_ANA    3          // South Analog Input
  #define WEST_ANA     4          // West Analog Input
  
  #define REF_OUT      7          // Reference Output
  #define V_REFERENCE  0          // Reference Input
  
  