SPOT Parser in the Console

We already had one Web version of a SPOT Parser, we now have one embedded in the Navigation Console. It allows the manipulation of the SPOT bulletins even if you are far from the Internet...

It also comes with a possibility to compose your own SPOT request.
At sea, you would compose your request (possibly with the data from the GPS), paste it into your Airmail client to send it through SailMail.
Once the response is in your inbox, you paste it in the utility featured above, and you have a graphical rendering of the SPOT data.
Enjoy!

Introducing the Headless Weather Wizard

Two things:

• The Weather Wizard runs on a Raspberry PI
• It can load (and save) a default composite, and reload it on a regular base

The idea is to run the Weather Wizard in some sort of batch mode, so it generates and stores composites on its file system, as long as you let it go.
You just need to run it this way:
On Windows:

set MEM_OPTIONS=-XX:NewSize=512m -XX:MaxNewSize=512m -Xmn768m -Xms1024m -Xmx1024m 
set MEM_OPTIONS=%MEM_OPTIONS% -XX:SurvivorRatio=1 -XX:PermSize=30m -XX:+UseParallelGC
set JAVA_OPTIONS=%EXTRA_JVM_PRM% %MEM_OPTIONS% %JAVA_OPTIONS% 
::
set PRMS=-composite:./patterns/01.Favorites/01.3.00.Pacific.Sfc.500.Tropic.GRIB.ptrn
set PRMS=%PRMS% -interval:360 
set PRMS=%PRMS% "-pattern:/yyyy/MM-MMM | Auto_ | yyyy_MM_dd_HH_mm_ss_z | waz"
::
set command=java %JAVA_OPTIONS% -client -classpath "%CP%" -Dheadless=true main.splash.Splasher %PRMS%
start "Headless Weather Wizard" %command%
  

On Linux:

MEM_OPTIONS=-XX:NewSize=512m -XX:MaxNewSize=512m -Xmn768m -Xms1024m -Xmx1024m 
MEM_OPTIONS=$MEM_OPTIONS -XX:SurvivorRatio=1 -XX:PermSize=30m -XX:+UseParallelGC
JAVA_OPTIONS=$EXTRA_JVM_PRM $MEM_OPTIONS $JAVA_OPTIONS
#
PRM1=-composite:./patterns/01.Favorites/01.3.00.Pacific.Sfc.500.Tropic.GRIB.ptrn
PRM2=-interval:360 
PRM3="-pattern:/yyyy/MM-MMM | Auto_ | yyyy_MM_dd_HH_mm_ss_z | waz"
#
java $JAVA_OPTIONS -client -classpath "$CP" -Dheadless=true main.splash.Splasher $PRM1 $PRM2 "$PRM3" &
  

Notice the parameters -composite:, -interval:, and -pattern:. Same for the System variable -Dheadless=true.
This means that the pattern mentioned in -composite: will be reloaded every 360 minutes, and stored as stated in the -pattern: parameter.

Introducing Console User-Exits

There are many things to do with the NMEA Data available in the cache, and the console is just doing a little - obvious - part of them.
In order for the users to implement their own features and ideas, we now provide a "user-exit" mechanism.
The user-exits are to be written in Java, and implement a specific interface named olivsoftdesktop.DesktopUserExitInterface, and defined as foillow:

      
     1  package olivsoftdesktop;
     2  
     3  public interface DesktopUserExitInterface
     4  {
     5    public void start();
     6    public void stop();
     7    public void describe();
     8  }
      
    

It could probably not be any simpler.

A Simple User-exit implementation

To develop your own features, you would need to put - at least - into your classpath:

• desktop.jar

And probably, to access the NMEA Data Cache:

• nmeaparser.jar
• nmeareader.jar
• coreutilities
• geomutil.jar

Then, write your code, and archive it into a jar-file.
Here is a simple implementation of this interface. This one evaluates the True Wind Speed every time a sentence is received from the NMEA station, and displays a message if the TWS is above 10 knots.
See how the NMEAReaderListener is registered.

      
     1  package olivsoftdesktop.sampleue;
     2  
     3  import nmea.event.NMEAReaderListener;
     4  import nmea.server.ctx.NMEAContext;
     5  import nmea.server.ctx.NMEADataCache;
     6  import ocss.nmea.parser.Angle360;
     7  import ocss.nmea.parser.Speed;
     8  import olivsoftdesktop.DesktopUserExitInterface;
     9  
    10  public class UserExitSample
    11    implements DesktopUserExitInterface
    12  {
    13    public UserExitSample()
    14    {
    15      super();
    16    }
    17  
    18    @Override
    19    public void start()
    20    {
    21      System.out.println("User exit is starting...");
    22      NMEAContext.getInstance().addNMEAReaderListener(new NMEAReaderListener()
    23      {
    24          @Override
    25          public void manageNMEAString(String nmeaString)
    26          {
    27  //        System.out.println("     ... From user exit, got NMEA Data [" + nmeaString + "]");
    28            NMEADataCache dc = NMEAContext.getInstance().getCache();
    29            double tws = ((Speed) dc.get(NMEADataCache.TWS)).getValue();
    30            double twd = ((Angle360) dc.get(NMEADataCache.TWD)).getValue();
    31            if (tws > 10 && !Double.isInfinite(tws))
    32            {
    33              System.out.println("Wind is over 10 kts:" + tws + ", TWD:" + twd);
    34              // TODO Send an email...
    35            }
    36          }
    37      });
    38    }
    39  
    40    @Override
    41    public void stop()
    42    {
    43      System.out.println("Terminating User exit");
    44    }
    45  
    46    @Override
    47    public void describe()
    48    {
    49      System.out.println("This is a simple user-exit example that shows howto register an NMEAReaderListener from your code.");
    50    }
    51  }
      
    

User-exit runtime

To have your user-exit to be taken care if, you need to:

• Archive it in a jar-file, and put the jar (along with the ones it may depend on) in one of the following directories
  • all-user-exits (recommended)
  • all-libs
  • all-3rd-party
• Mention the name of the user-exit in the command-line parameters, like -ue:myspecial.feature.SuperUserExit. For the example above, the parameter would be -ue:olivsoftdesktop.sampleue.UserExitSample.

And that's it. This works from the console, as well as from the headless one.

A more complex sample

Here is the scenario:
You have an internet connection on the boat, it is docked or anchored in the harbor.
From wherever you are, you want to know what the wind is like where the boat is.
This user-exit monitors the True Wind Speed (TWS), and send an email when it is above a given threshold. It looks at the wind speed every X minutes, the X comes from a configuration file (email.properties) that can be edited.

      
     1  package olivsoftdesktopuserexits;
     2  
     3  import java.io.FileInputStream;
     4  import java.text.DecimalFormat;
     5  import java.text.SimpleDateFormat;
     6  import java.util.Calendar;
     7  import java.util.Date;
     8  import java.util.Properties;
     9  import java.util.TimeZone;
    10  import nmea.server.ctx.NMEAContext;
    11  import nmea.server.ctx.NMEADataCache;
    12  import ocss.nmea.parser.Angle360;
    13  import ocss.nmea.parser.GeoPos;
    14  import ocss.nmea.parser.Speed;
    15  import ocss.nmea.parser.UTCDate;
    16  import olivsoftdesktop.DesktopUserExitInterface;
    17  import olivsoftdesktopuserexits.emailutil.EmailSender;
    18  
    19  public class DesktopEmailSender
    20    implements DesktopUserExitInterface
    21  {
    22    private final static SimpleDateFormat SDF = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
    23    private final static DecimalFormat DF22   = new DecimalFormat("##0.00 'kts'");
    24    private final static DecimalFormat DF30   = new DecimalFormat("##0'\272'");
    25    private static String SEND_PROVIDER = "google";
    26    private Thread watcher = null;
    27    private boolean keepWatching = true;
    28    private EmailSender sender = null;
    29  
    30    private double windThreshold = -1;
    31    private long betweenLoops = 600 * 1000L; // 10 minutes default
    32  
    33    public DesktopEmailSender()
    34    {
    35      super();
    36    }
    37  
    38    @Override
    39    public void start()
    40    {
    41      System.out.println("Method 'start':" + this.getClass().getName() + " User exit is starting...");
    42      Properties props = new Properties();
    43      String propFile = "email.properties";
    44      try
    45      {
    46        FileInputStream fis = new FileInputStream(propFile);
    47        props.load(fis);
    48      }
    49      catch (Exception e)
    50      {
    51        System.err.println("email.properies file problem..., from " + System.getProperty("user.dir"));
    52        throw new RuntimeException("File not found:email.properies");
    53      }
    54      SEND_PROVIDER = props.getProperty("ue.preferred.provider", SEND_PROVIDER);
    55      sender = new EmailSender(SEND_PROVIDER);
    56      try
    57      {
    58        windThreshold = Double.parseDouble(props.getProperty("ue.wind.threshold"));
    59        System.out.println("Will send emails when the wind is above [" + windThreshold + "]");
    60      }
    61      catch (NumberFormatException nfe)
    62      {
    63        throw new RuntimeException("Bad wind threshold:" + props.getProperty("ue.wind.threshold"));
    64      }
    65      try
    66      {
    67        betweenLoops = Long.parseLong(props.getProperty("ue.between.loops.in.minute"));
    68      }
    69      catch (NumberFormatException nfe)
    70      {
    71        throw new RuntimeException("Bad Loop interval:" + props.getProperty("ue.between.loops.in.minute"));
    72      }
    73      final long _betweenLoops = betweenLoops;
    74      watcher = new Thread()
    75        {
    76          private boolean started = false;
    77          private final long BETWEEN_LOOPS = _betweenLoops * 60 * 1000;
    78          private final long TEN_SECONDS   =  10000L;
    79          private long waitTime = BETWEEN_LOOPS;
    80          public void run()
    81          {
    82            while (keepWatching)
    83            {
    84              waitTime = BETWEEN_LOOPS;
    85              NMEADataCache dc = NMEAContext.getInstance().getCache();
    86              try
    87              {
    88                double tws = ((Speed) dc.get(NMEADataCache.TWS)).getValue();
    89                double twd = ((Angle360) dc.get(NMEADataCache.TWD)).getValue();
    90                String date = "";
    91                UTCDate utcDate = (UTCDate)NMEAContext.getInstance().getCache().get(NMEADataCache.GPS_DATE_TIME);
    92                if (utcDate != null && utcDate.getValue() != null)
    93                {
    94                  Date d = utcDate.getValue();
    95                  Calendar cal = Calendar.getInstance();
    96                  cal.setTime(d);
    97                  cal.setTimeZone(TimeZone.getTimeZone("Etc/UTC"));
    98                  date = SDF.format(cal.getTime());
    99                }
   100                String pos = "";
   101                try { pos = ((GeoPos)dc.get(NMEADataCache.POSITION)).toString(); } catch (Exception ex) {}
   102                if (!started)
   103                {
   104                  started = true;
   105                  System.out.println(" -- User exit started for good.");
   106                }
   107                if (tws > windThreshold && !Double.isInfinite(tws))
   108                {
   109                  String alertMessage =
   110                    (date.trim().length() > 0 ? "Date:" + date + "\n": "") +
   111                    (pos.trim().length() > 0 ? "Pos:" + pos + "\n" : "") +
   112                    "Wind is over " + DF22.format(windThreshold) + ":" + DF22.format(tws) + ", TWD:" + DF30.format(twd);
   113                  System.out.println(alertMessage);
   114                  // Send an email...
   115                  try
   116                  {
   117                    sender.send(alertMessage);
   118                    System.out.println("Email sent.");
   119                  }
   120                  catch (Exception ex)
   121                  {
   122                    System.err.println("Sending email failed through [" + SEND_PROVIDER + "]");
   123                    ex.printStackTrace();
   124                  }
   125                }
   126              }
   127              catch (NullPointerException npe)
   128              {
   129                // Just wait til next time...
   130                System.out.println("Cache not initialized (yet)");
   131                waitTime = TEN_SECONDS;
   132              }
   133              synchronized (this)
   134              {
   135                System.out.println("  ...User exit going to wait, at " + new Date().toString() + " (will wait for " + (waitTime / 1000) + " s)");
   136                try { wait(waitTime); }
   137                catch (InterruptedException ie)
   138                {
   139                  System.out.println("Told to stop!");
   140                  keepWatching = false;
   141                }
   142              }
   143            }
   144            System.out.println("Stop waiting.");
   145          }
   146        };
   147      keepWatching = true;
   148      watcher.start();
   149    }
   150  
   151    @Override
   152    public void stop()
   153    {
   154      System.out.println(this.getClass().getName() + " is terminating");
   155      keepWatching = false;
   156      synchronized (watcher)
   157      {
   158        watcher.notify();
   159      }
   160    }
   161  
   162    @Override
   163    public void describe()
   164    {
   165      System.out.println("Polls the NMEA Cache on a regular base, and sends an email if the TWS is above a given threshold.");
   166      System.out.println("Driven by a properties file named email.properties, in the all-scripts directory.");
   167    }
   168  }      
      

All the sources of this example.

Possibilities are endless. The limit is your imagination.
Combining the two examples above, you can as well gather all the data into a single document (XML, json, etc), and send it through email on a regular base, so it can be rendered by the receipient.
Etc, etc...

How to do it for yourself, step by step

1. Download all the sources, in the zip mentionned above
2. Extract it is a new clean directory
3. Make sure the jar mail.jar is in your all-3rd-party directory
4. Make sure you have installed a JDK in your environment
5. In a system console, navigate to the directory where you unzipped the sources
6. If it does not exist, create a classes directory. Make sure it is empty
7. Compile the code:
   On Windows

    Prompt> set OLIV_HOME=D:\OlivSoft
    Prompt> set CP=%OLIV_HOME%\all-3rd-party\mail.jar
    Prompt> set CP=%CP%;%OLIV_HOME%\all-libs\nmeaparser.jar
    Prompt> set CP=%CP%;%OLIV_HOME%\all-libs\nmeareader.jar
    Prompt> set CP=%CP%;%OLIV_HOME%\all-libs\desktop.jar
    Prompt> set CP=%CP%;%OLIV_HOME%\all-libs\geomutil.jar
    Prompt> javac -d classes -sourcepath src -cp %CP% src\olivsoftdesktopuserexits\*.java
           

   On Linux

    
    Prompt> bash
    Prompt> OLIV_HOME=/usr/OlivSoft
    Prompt> CP=$OLIV_HOME/all-3rd-party/mail.jar
    Prompt> CP=$CP:$OLIV_HOME/all-libs/nmeaparser.jar
    Prompt> CP=$CP:$OLIV_HOME/all-libs/nmeareader.jar
    Prompt> CP=$CP:$OLIV_HOME/all-libs/desktop.jar
    Prompt> CP=$CP:$OLIV_HOME/all-libs/geomutil.jar
    Prompt> javac -d classes -sourcepath src -cp $CP src/olivsoftdesktopuserexits/*.java
           

   Make sure you do not see any error.
8. Archive the generated classes:
   On Windows

    
    Prompt> cd classes
    Prompt> jar -cvf ..\emailUserExit.jar *
           

   On Linux

    
    Prompt> cd classes
    Prompt> jar -cvf ../emailUserExit.jar *
           

9. Copy the archive in the all-user-exits directory
   On Windows

    
    Prompt> cd ..
    Prompt> copy *.jar %OLIV_HOME%\all-user-exits
           

   On Linux

    
    Prompt> cd ..
    Prompt> cp *.jar $OLIV_HOME/all-user-exits
           

   Copy email.properties in the all-scripts directory
   On Windows

    
    Prompt> copy email.properties %OLIV_HOME%\all-scripts
           

   On Linux

    
    Prompt> cp email.properties $OLIV_HOME/all-scripts
           

   You are almost done...
10. Modify the line that starts the console, so it takes your work in account:
    On Windows

     
    set COMMAND=java %JAVA_OPTIONS% -classpath %CP% olivsoftdesktop.OlivSoftDesktop %HEADLESS_OPTIONS% -ue:olivsoftdesktopuserexits.DesktopEmailSender
    start "Headless Console (User-Exit)" %COMMAND%
            

    On Linux

     
    java $JAVA_OPTIONS -classpath $CP olivsoftdesktop.OlivSoftDesktop $HEADLESS_OPTIONS -ue:olivsoftdesktopuserexits.DesktopEmailSender &
            

    That's it!
    Important: Do not forget to edit and modify email.properties, so it matches your environment, and your needs.

And all this runs just fine on a Raspberry PI, I've tested it.

Multiple Access, for real

Now we've setup the ad-hoc network from the Raspberry PI reading the NMEA Data, we can simultaneously access the data, from several devices connected on the ad-hoc network defined on the boat, from the Raspberry PI itself:

Swing Console from a laptop

OpenCPN from a laptop

HTML Console from a laptop

HTML Console from an iPad

HTML Console from an iPhone

All the pictures above were taken with all the programs on the devices running simultaneously.
A small glitch I need to address: Android does not want to connect to an ad-hoc network. I need to fix that, more to come soon.

NMEA with Raspberry PI: All Good!

The last step - after this one - was not as straight forward. But finally, everything works fine.
The idea was to use PI4J to read the serial port (/dev/ttyAMA0). All the tests I made with PI4J were all very positive, but apparently, there is a bug when the baud rate is 4800. And unfortunately, this is the one we need.
But as reading a USB port (/dev/ttyUSB0) was not a problem, a simple adapter (serial 9 pin to USB) fixed everything. And on Linux (Raspberry PI runs Linux, a tweaked version of Debian), no driver or any such thing is required. Plug it in, and boom! It works.

The Raspberry PI reads the serial port with the headless console, and rebroadcasts everything appropriately.
The NMEA Console and OpenCPN can use TCP to get the data, The html5 Console uses HTML..., everything goes seamlessly. For less than 700mA. And around $50.
We will detail later all the steps to go through to get this done anywhere. This is just an easy check list.
And we'll built a nice box to host all this. The Raspberry, an optional small screen, and possibly a small keyboard.
More soon.

And just to give you a taste of what will come next,node.js works like a charm on the Raspberry PI, and the WebSocket protocol works as if it had been designed for this platform... That is going to seriously rock.

To summarize

This project goes along with the NMEA console, found here.

The main points this project addresses:

• Serial ports (most of the data we're interested in come through a serial port) are accessed exclusively. Only one program at a time can access the data. I had the problem on the ketch, when the cartography soft was accessing the data port (to plot the boat on the chart), the console (the one evaluating current and performances) had to wait.
• The laptop you can use to read the data draws a substantial amount of electricity (around 10W is not unusual).
• Several devices on the boat (tactician, driver, navigator, trimmers) might need to have simultaneous access to the data, and they might need to be already processed and smoothed (damped)

The various devices needing access to the data might not run the same Operating System (MacOS, iOS, Android, Windows, Linux...). We assumed here that they have a network access, and a browser supporting HTML5 (the tests I made for this particular point are positive).
So, here is the story:

1. The Raspberry PI creates its own ad-hoc network when it boots, and you start on it a utility that reads the data from the serial (or whatever) port connected to the NMEA station
2. The data are read, and stored on the raspberry in some cache (a hashmap).
3. The data are logged (optional), and processed (true wind is calculated, current is evaluated, VMG - on the wind or on the mark, performance, are evaluated). Those data are cached as well. Those calculations require some parameters to be set (max leeway, deviation curves, polars of the boat, some coefficients for the instruments, etc), they are available on the Raspberry PI.
4. The data rebroadcasted on TCP, UDP, and HTML (also possibly RMI; I dropped GPSd). You can select one or more of those channels for rebroadcasting.

Basically, this is all the RaspPi is doing.

The SD card containing the OS of the PI needs to be 4Gb big, minimal recommended. Mine is 8, and it can go beyond 32. This allows DAYS of logging.

Now, when a device from the boat wants to see what's going on (i.e. visualize the data), it connects to the boat's ad-hoc network. Then, depending on its possibilities and needs, it can use the NMEA Console (that one can read any channel for its data input), or the HTML5 Console (at the bottom of this page).

The chart plotting program (like OpenCPN) can use the exact same data stream.
And when you're done watching your device, you can turn it off, hibernate it, what not, the RaspPi keeps reading and broadcasting.

The RaspPi does not take more than 700mA.
And it costs less than $50.
The RaspPi does not need any keyboard or screen. (I use SSH from a laptop to start the reading program on it).
The main points are:

• Low consumption (and low price, if it makes any sense in this context)
• Data rebroadcasting
• Logging (ages of logging).
  I log VWR, RMC, MWV, RMB, VHW, VLW, HDG, MTW and GLL. It's about 1 Mb per hour.
  One day would be 24 Mb. One week around 168 Mb. Peanuts.

I have a lot of data, some logged during our Polynesian trip, I can replay them. This story seems to work.

I was very interested during the recent America's Cup, to see all the crews watching several kind of devices..., many had those displays on their fore-arms, tacticians had some iPad-like devices, fasten on their bellies with some shock-cords and velcro..., it kind of rang a bell! Those boats had for sure way more sensors that just an NMEA station (up to 3000 sensors for Oracle, I heard), but I believe that there is already a LOT to do with the data you can get from a regular NMEA station.

Once the ad-hoc network is setup, the crew members can even use their smart phone to access it, and visualize the HTML5 Console. That actually enhances one point: All the technology is here - nothing has been built or invented specially for this project. It's all about getting access to it with existing devices and techniques. Everyone (including me!) now has a smartphone, Linux has been around for ages, NMEA is one of the (if not THE) oldest standards in IT... And again, a small device you can get for less that $50 makes it all possible!
I like that.

Tropical phenomenons, Pacific, fall 2013

We've had quite a few tropical phenomenons in the Pacific since the end of August... Here is a list - still open - of what we've had, along with the time they were active, and their highest strength. Wind speeds are in knots. 60 G 75 is to be read 60 knots, gusting 75 knots.

Sep 01-02	TS Kiko, 60 G 75
Sep 13-16	TS Man-Yi, 60 G 75
Sep 17-18	Typhoon Usagi, 65 G 80
Sep 13-16	TS Man-Yi, 60 G 75
Sep 19	Hurricane Manuel, 65 G 80
Sep 21-27	Typhoon Pabuk, 90 G 110
Oct 01-04	Typhoon Fitow, 85 G 105
Oct 04-06	Typhoon Danas, 95 G 115
Oct 11-16	Typhoon Wipha, 115 G 140
Oct 16-30	Super Typhoon Francisco, 140 G 170 Super Typhoon Lekima, 140 G 170, Hurricane Raymond, 95 G 105
Nov 04-now	Super Typhoon Haiwan, 165 G 200

As a reminder, a hurricane (force 12 on the Beaufort scale) is over 64 knots.
Over 64 knots, it's a Category One hurricane.
Over 82 knots, it's a Category Two hurricane.
Over 95 knots, it's a Category Three hurricane.
Over 112 knots, it's a Category Four hurricane.
Over 136 knots, it's a Category Five hurricane.

Hurricanes and Typhoons are similar phenomenons. Hurricanes belong to the East Pacific, Typhoons to the West Pacific.

We also note that the Beaufort scale does not mention any such thing as a "Super Storm". You have Storm, Violent Storm, and Hurricane...
"Super Storm" is something invented by some journalists.

For Navigatrix users of the WeatherWizard

Apparently, the soft has been installed as root, and some write permissions are not granted to everyone.
That makes it difficult to write on the file system, like when downloading a file!
To fix that, you need to go to a Console, and enter the following commands:

 Prompt> cd /opt/WeatherWizard
 Prompt> sudo find . -name '*' -exec chown $USER {} \;

You might as well change the group of the same files. If your group is "mygrp", then just type:

 Prompt> cd /opt/WeatherWizard
 Prompt> sudo find . -name '*' -exec chgrp mygrp {} \;

Be careful, all characters are important.
That's a bit cryptic, but that should work!

From Scratch to NMEA Re-broadcasting on TCP, with a Raspberry PI

This post will demonstrate how to connect a Raspberry PI on some NMEA input - a GPS in this case - to re-broadcast all its data using other protocols, HTTP and TCP in this case.
The cool thing about this configuration is that:

• As many devices as you want can access the NMEA data
• The Raspberry PI only draws 700 mA
• When they're done using rthe NMEA data, devices (laptops, tablets...) can shutdown, the NMEA data will still be read and available whenever a device connects on the Raspberry Pi's network

The NMEA data being read can also be logged on the Raspberry PI, if necessary.

We assume that you already have a Raspberry PI, along with its power supply (AC or DC, whatever).
We will show how to setup everything so the Raspberryt PI reads the NMEA data, and re-broadcasts them. As an example, we will show how to consume them from OpenCPN.
We will also need to edit several configuration files and other scripts. You can use any editor you wish, "nano" can do the job, I myself prefer "vi". At the end of the day, that's the same, only the result is important.

Requirements

First, flash the SD card, as explained here. I used the Raspbian image. Comes with Java.
Next, we will require several softwares to be installed on the Raspberry PI, some are necessary, others are convenient.

An FTP server

This one will be very convenient when you will need to transfer files on you Raspberry PI.
To install, type:

 Prompt> sudo apt-get install vsftpd
    

Then edit (sudo edit) /etc/vsftpd.conf:

 anonymouse_enable=NO
 local_enable=YES
 write_enable=YES
 local_umask=022
 chroot_local_user=YES
 user_sub_token=$USER
 local_root=/home/$USER/ftp
    

Start this ftp as a service on the PI:

  
  Prompt> sudo service vsftpd restart
    

Install RXTX Java libraries

Read this good article.
Just type:

 Prompt> sudo apt-get install librxtx-java
    

We will see in the next section what to do with this.

Fing

A very cool utility. Combination of Find and Ping.

 Prompt> wget http://www.overlooksoft.com/packages/download?plat=arm
 Prompt> sudo dpkg -i overlook-fing-2.3.deb
 Prompt> sudo apt-get install libpcap*
    

and finally:

 Prompt> sudo fing
    

OlivSoft

You have just installed the libraries you need to use the serial ports (Serial or USB), now we need to modify the launching script to take that in account.
Make sure you have the last version of the soft, up to date.
It is available on Google Code, in the download section.
The best way to do that is probably to install it on a box connected to the internet, and to let the software update itself.
Then you can transfer all the directory where it is installed (using FTP) on the Raspberry PI.
Once this is done, navigate to the all-scripts directory, and edit the script named olivsoft.
You can add a line in the menu:

  echo \| P for Weather Wizard, with http proxy 
  echo \| S for NMEA Sniffer
  echo \| H for Headless NMEA Console
  echo \| POL for Polar Tool
    

... and then the corresponding execution definition:

    ...
  elif [ $choice = "H" ] || [ $choice = "h" ] 
  then
    JAVA_OPTIONS="$JAVA_OPTIONS -Dverbose=false"
    JAVA_OPTIONS="$JAVA_OPTIONS -Dheadless=yes"
    JAVA_OPTIONS="$JAVA_OPTIONS -Dserial.port=/dev/ttyUSB0"
    JAVA_OPTIONS="$JAVA_OPTIONS -Djava.library.path=/usr/lib/jni"
    #
    HEADLESS_OPTIONS="-output=HTTP:9999"
    HEADLESS_OPTIONS="$HEADLESS_OPTIONS -output=TCP:7001"
    # HEADLESS_OPTIONS="$HEADLESS_OPTIONS -output=FILE:.\logged-data\headless.nmea
    java -client -Xms512m -Xmx1024m -classpath $CP $JAVA_OPTIONS olivsoftdesktop.OlivSoftDesktop $HEADLESS_OPTIONS
  elif ...
    

Notice that /dev/ttyUSB0 is the USB port the GPS in connected on. In this case, the data will be re-broadcasted on TCP, port 7001, as well as on HTTP port 9999.
We will see below how to start the program.

Create an ad-hoc network, from the Raspberry PI

Read this good article.
Make a backup:

 Prompt> sudo cp /etc/network/interfaces /etc/network/interfaces_backup
    

Then edit (sudo edit) /etc/network/interfaces:

 auto lo
 iface lo inet loopback
 iface eth0 inet dhcp
 
 auto wlan0
 iface wlan0 inet static
   address 192.168.1.1
   netmask 255.255.255.0
   wireless-channel 1
   wireless-essid RPiOnTheBoat
   wireless-mode ad-hoc
    

In the lines above, RPiOnTheBoat will be the name of your ad-hoc network.
Restart wlan0 (wlan0 is the name of the wireless network interface).

 Prompt> sudo ifdown wlan0
 Prompt> sudo ifup wlan0
    

(reboot in case you have an error message)

Then we might need a DHCP Server:

 Prompt> sudo apt-get update
 Prompt> sudo apt-get install dhcp3-server
    

Then edit (sudo edit) /etc/dhcp/dhcpd.conf

 ddns-update-style interim;
 default-lease-time 600;
 max-lease-time 7200; 
 authoritative;
 log-facility local7;
 subnet 192.168.1.0 netmask 255.255.255.0 {
   range 192.168.1.5 192.168.1.150;
 }
    

Reboot..., all should be all set!
Let's if that's true.

Run it

Connect the things first:

Only the Wireless dongle is in

Plug the SD Card in (contains the OS)

Plug in the GPS

Connect the power supply

Connecting the power supply will boot the device. Now, wait a couple of seconds for Linux to boot, and we are going to connect to the Raspberry PI from another machine, using ssh.
Notice in the steps above, that there is no mouse, no keyboard, and no screen connected on the Raspberry PI. We could have done so. But we didn't.
To demonstarte the full compatibility of this scenario, we will do the subsequent operations from a Windows box.

Connect to the Raspberry PI's ad-hoc network

The wireless networks are usually available in the Windows taskbar. If not, open your Network Control Panel, you'll find it there.

Notice the network's name (RPiOnTheBoat), this is the one you defined.
Then, we will use ssh (PuTTY) to start the re-broadcast:

Connect with your username (default: pi) and password (default: raspberry), and cd to olivsoft, and start the script olivsoft:

 Prompt> ./olivsoft
    

It's on its way! You can leave the session if you wish, the process will keep going.
To stop it:
Re-connect on the Raspberry PI with ssh
Find the process, by typing:

 Prompt> ps -ef | grep java    
    

Then send it a SIGTERM signal:

 Prompt> kill -SIGTERM 2493
    

Where 2493 is the process id. This way, the process will shut down nicely (by design, it understands that signal, which would be a Ctrl+C from the command line).

The process being up and running, define a network connection in OpenCPN:

Notice the Address, the one you have defined.
Click Apply...

See the top right, the GPS is connected. As you can see in the NMEA log.
You can connect like this with as many devices as you want.
Voilà!

Next, we will try with the full NMEA station, with Pi4j. Then the HTML5 console will also be available, from http://192.168.1.1:9999/html5/console.html.

Investigating the Raspberry PI

The more I play with it, the more I like it... It's so small - and so cheap - and it is a real Linux system, based on Debian. It comes with Java. It runs from a small SD card (4Gb recommended minimum). All the info are available on the Raspberry PI web site.

Development config

Minimal config

The GPIO can be managed with PI4J, works like a charm. Example:

----------------------------------------------------
HARDWARE INFO
----------------------------------------------------
Serial Number     :  00000000a36c8782
CPU Revision      :  7
CPU Architecture  :  7
CPU Part          :  0xb76
CPU Temperature   :  49.8
CPU Core Voltage  :  1.2
MIPS              :  697.95
Processor         :  ARMv6-compatible processor rev 7 (v6l)
Hardware Revision :  000e
Is Hard Float ABI :  true
Board Type        :  ModelB_Rev2
----------------------------------------------------
MEMORY INFO
----------------------------------------------------
Total Memory      :  459505664
Used Memory       :  240529408
Free Memory       :  219484160
Shared Memory     :  0
Memory Buffers    :  20328448
Cached Memory     :  141778944
SDRAM_C Voltage   :  1.2
SDRAM_I Voltage   :  1.2
SDRAM_P Voltage   :  1.23
----------------------------------------------------
OPERATING SYSTEM INFO
----------------------------------------------------
OS Name           :  Linux
OS Version        :  3.6.11+
OS Architecture   :  arm
OS Firmware Build :  4f9d19896166f46a3255801bc1834561bf092732 (clean) (release)
OS Firmware Date  :  Sep  1 2013 23:31:02
----------------------------------------------------
JAVA ENVIRONMENT INFO
----------------------------------------------------
Java Vendor       :  Oracle Corporation
Java Vendor URL   :  http://java.oracle.com/
Java Version      :  1.7.0_40
Java VM           :  Java HotSpot(TM) Client VM
Java Runtime      :  Java(TM) SE Runtime Environment
----------------------------------------------------
NETWORK INFO
----------------------------------------------------
Hostname          :  raspberrypi
IP Addresses      :  192.168.1.251
FQDN              :  raspberrypi.att.net
Nameserver        :  192.168.1.254
----------------------------------------------------
CODEC INFO
----------------------------------------------------
H264 Codec Enabled:  true
MPG2 Codec Enabled:  false
WVC1 Codec Enabled:  false
----------------------------------------------------
CLOCK INFO
----------------------------------------------------
ARM Frequency     :  700000000
CORE Frequency    :  250000000
H264 Frequency    :  0
ISP Frequency     :  250000000
V3D Frequency     :  250000000
UART Frequency    :  3000000
PWM Frequency     :  0
EMMC Frequency    :  100000000
Pixel Frequency   :  108000000
VEC Frequency     :  0
HDMI Frequency    :  163683000
DPI Frequency     :  0

The first goal will be to have such a device running in the chart table, reading the NMEA Data (connected on the NMEA Station through its serial port, read with GPIO, as mentioned above), and re-broadcasting the data on HTTP, TCP or UDP. The re-broadcasting part has been tested (see here), with logged data.
Next:

• Connect the serial port, and read it from Pi4J
• Create an ad-hoc network FROM the Raspberry PI

This way, several applications can use the NMEA Data, simultaneously. It has been tested with the NMEA Console, and OpenCPN, with TCP and UDP. The HTTP re-broadcast can be used from an HTML5 browser, from a laptop or a tablet, connected on the boat's ad-hoc network.

HTML5 NMEA Console, on a tablet

South California Free Anchorages

Working on it. There is this site, quite interesting, and I'm trying to use Google Maps as well.

View Free anchorages in a larger map

More to come soon, stay tuned.