Connect and read an external GPS, part II
Where is the Sun?

      

     1  package nmea;
     2  
     3  import com.pi4j.io.serial.Serial;
     4  import com.pi4j.io.serial.SerialDataEvent;
     5  import com.pi4j.io.serial.SerialDataListener;
     6  import com.pi4j.io.serial.SerialFactory;
     7  
     8  import java.util.List;
     9  
    10  import ocss.nmea.api.NMEAEvent;
    11  import ocss.nmea.api.NMEAListener;
    12  import ocss.nmea.api.NMEAReader;
    13  
    14  public class CustomNMEASerialReader 
    15       extends NMEAReader 
    16  {
    17    private int baudRate = 4800;
    18    private CustomNMEASerialReader instance = this;
    19    
    20    public CustomNMEASerialReader(List<NMEAListener> al, int br)
    21    {
    22      super(al);
    23      baudRate = br;
    24    }
    25  
    26    @Override
    27    public void read()
    28    {
    29      if (System.getProperty("verbose", "false").equals("true")) 
    30        System.out.println("From " + this.getClass().getName() + " Reading Serial Port.");
    31      
    32      super.enableReading();
    33      
    34      // Opening Serial port
    35      try
    36      {
    37        final Serial serial = SerialFactory.createInstance();
    38  
    39        // create and register the serial data listener
    40        serial.addListener(new SerialDataListener()
    41        {
    42          @Override
    43          public void dataReceived(SerialDataEvent event)
    44          {
    45        //  System.out.print(/*"Read:\n" + */ event.getData());
    46            instance.fireDataRead(new NMEAEvent(this, event.getData()));
    47          }
    48        });
    49        System.out.println("Opening port [" + Serial.DEFAULT_COM_PORT + "]");
    50        serial.open(Serial.DEFAULT_COM_PORT, baudRate);
    51      }
    52      catch (Exception ex)
    53      {
    54        ex.printStackTrace();
    55      }
    56      // Reading on Serial Port
    57      System.out.println("Port is open...");
    58    }
    59  }
      
    

      

     1  package nmea;
     2  
     3  import calculation.AstroComputer;
     4  import calculation.SightReductionUtil;
     5  
     6  import java.text.DecimalFormat;
     7  
     8  import java.util.Calendar;
     9  import java.util.TimeZone;
    10  
    11  import ocss.nmea.api.NMEAClient;
    12  import ocss.nmea.api.NMEAEvent;
    13  import ocss.nmea.api.NMEAListener;
    14  import ocss.nmea.parser.GeoPos;
    15  import ocss.nmea.parser.RMC;
    16  import ocss.nmea.parser.StringParsers;
    17  
    18  public class CustomNMEAReader extends NMEAClient
    19  {
    20    private final static DecimalFormat DFH = new DecimalFormat("#0.00'\272'");
    21    private final static DecimalFormat DFZ = new DecimalFormat("##0.00'\272'");
    22    
    23    private static GeoPos prevPosition = null;
    24    private static long   prevDateTime = -1L;
    25  
    26    public CustomNMEAReader()
    27    {
    28      super();
    29    }
    30    
    31    @Override
    32    public void dataDetectedEvent(NMEAEvent e)
    33    {
    34  //  System.out.println("Received:" + e.getContent());
    35      manageData(e.getContent().trim());
    36    }
    37  
    38    private static CustomNMEAReader customClient = null;  
    39    
    40    private static void manageData(String sentence)
    41    {
    42      boolean valid = StringParsers.validCheckSum(sentence);
    43      if (valid)
    44      {
    45        String id = sentence.substring(3, 6);
    46        if ("RMC".equals(id))
    47        {
    48       // System.out.println(line);
    49          RMC rmc = StringParsers.parseRMC(sentence);
    50       // System.out.println(rmc.toString());
    51          if (rmc != null && rmc.getRmcDate() != null && rmc.getGp() != null)
    52          {
    53            if ((prevDateTime == -1L || prevPosition == null) ||
    54                (prevDateTime != (rmc.getRmcDate().getTime() / 1000) || !rmc.getGp().equals(prevPosition)))
    55            {
    56              Calendar current = Calendar.getInstance(TimeZone.getTimeZone("etc/UTC"));
    57              current.setTime(rmc.getRmcDate());
    58              AstroComputer.setDateTime(current.get(Calendar.YEAR), 
    59                                        current.get(Calendar.MONTH) + 1, 
    60                                        current.get(Calendar.DAY_OF_MONTH), 
    61                                        current.get(Calendar.HOUR_OF_DAY), 
    62                                        current.get(Calendar.MINUTE), 
    63                                        current.get(Calendar.SECOND));
    64              AstroComputer.calculate();
    65              SightReductionUtil sru = new SightReductionUtil(AstroComputer.getSunGHA(),
    66                                                              AstroComputer.getSunDecl(),
    67                                                              rmc.getGp().lat,
    68                                                              rmc.getGp().lng);
    69              sru.calculate();
    70              Double he = sru.getHe();
    71              Double  z = sru.getZ();
    72              System.out.println(current.getTime().toString() + ", He:" + DFH.format(he)+ ", Z:" + DFZ.format(z) + " (" + rmc.getGp().toString() + ")");
    73            }
    74            prevPosition = rmc.getGp();
    75            prevDateTime = (rmc.getRmcDate().getTime() / 1000);
    76          }
    77          else
    78          {
    79            if (rmc == null)
    80              System.out.println("... no RMC data in [" + sentence + "]");
    81            else
    82            {  
    83              String errMess = "";
    84              if (rmc.getRmcDate() == null)
    85                errMess += ("no Date ");
    86              if (rmc.getGp() == null)
    87                errMess += ("no Pos ");
    88              System.out.println(errMess + "in [" + sentence + "]");
    89            }
    90          }
    91        }
    92      }    
    93      else
    94        System.out.println("Invalid data [" + sentence + "]");
    95    }
    96  
    97    public static void main(String[] args)
    98    {
    99      System.setProperty("deltaT", System.getProperty("deltaT", "67.2810")); // 2014-Jan-01
   100  
   101      int br = 4800;
   102      System.out.println("CustomNMEAReader invoked with " + args.length + " Parameter(s).");
   103      for (String s : args)
   104      {
   105        System.out.println("CustomNMEAReader prm:" + s);
   106        try { br = Integer.parseInt(s); } catch (NumberFormatException nfe) {}
   107      }
   108      
   109      customClient = new CustomNMEAReader();
   110        
   111      Runtime.getRuntime().addShutdownHook(new Thread() 
   112        {
   113          public void run() 
   114          {
   115            System.out.println ("Shutting down nicely.");
   116            customClient.stopDataRead();
   117          }
   118        });    
   119      customClient.initClient();
   120      customClient.setReader(new CustomNMEASerialReader(customClient.getListeners(), br));
   121      customClient.startWorking(); // Feignasse!
   122    }
   123  
   124    private void stopDataRead()
   125    {
   126      if (customClient != null)
   127      {
   128        for (NMEAListener l : customClient.getListeners())
   129          l.stopReading(new NMEAEvent(this));
   130      }
   131    }
   132  }