The XO Computer for Navigation

[phiggins]

Actually I was documenting it last night just in case I had to do it again. Here it is:

1. Establish connection to internet.
2. Open terminal screen and enter:
wget http://www.navgator.com/download/Set...x-3_1_1.tar.gz
3. uncompress and install Mariner:
tar xvf SetupMariner-Linux-3_1_1.tar.gz
4. Give your usrid access to uucp (group 14) and the lock (group 54):
su - enter (to be a super user)
vi /etc/group - enter
i enter (puts vi in insert mode)
change the line: "uccp::14:uucp" to "uccp::14:uucp,olpc" where olpc is your userid.
change line: "lock::54:" to "lock::54lpc" where olpc is your userid.
Note: the little happy face above is a colon followed by olpc
press esc key
enter: ZZ then press enter to save file
enter: exit to go back to your userid
6. Start Navgator by entering: Mariner/mariner
------------------------------------------------------------------------------
7. Mariner should start.

I also loaded it onto my windows PC because it was easier to figure out how to use it then did the same thing on XO.

To use some charts I wrote some to the SD card on my PC then moved it to the XO. To load them into Mariner open File Charts... It will have file tree scroll down to the media folder and click on it. It takes a long time to open. When it finally opens click on your SD card name, keep going down until you see the actually .kap and .bsb files. Click on first one and scroll down to last one and press shift click to select them all. Then press Import, then Done

To bring up a chart: right click on one of the panels and select Add Instrument and slect Chart viewer.

Right click again to get Select Chart and - from list. Select the one of .kap files (not the BSB ones) and voila.

Wasn't that easy!

Paul

[drewc]

Paul, thanks so much for documenting these steps. I followed exactly and was able to get the app going with a few minor tweaks, most importantly a REBOOT after editing the uucp and lock entries. I have also noticed that upon exiting the Navgator app I get a "javax.sound.sampled.LineUnvailableException" regarding something to do with a "getClip" request that fails due to "little-endian not supported"...I suspect I have not set up some kind of sound resource or capability. While it doesn't seem to bother the app itself it is curious.
One final question (I hope!)...were you successful in locating a USB-Serial adapter for your GPS that works with the XO drivers? Thanks again for your help!

Thanks, Drew

[phiggins]

Drew,

I also get that message. Someting to reslove with Navgator later.

As for the USB to serial: No still not working. I tried the two cables I had and neither worked so I went out and bought a new one that someone said did work. It did not work either. I am in working with Navagator folks trying to fix this.

I did a:
yum install pyserial

so I could write a small program in Python to test the '/dev/ttyUSB0' port and it was able to open the port successfully. That seems to suggest that the Mariner program has a problem. Will let you know what happens.

Paul

[drewc]

Paul, thanks again for the quick response. Guess we're really beta testers for the XO now! Another item I just tripped over...I loaded up a USB memory stick with some BSBs/KAPs I downloaded from the NOAA site..the charts work well with my MAC and PC-based nav programs but Navgator complains about "bad format" when I attempt to open them on the XO (yes they are "real" files and not zipped.) Any ideas?

Drew

[phiggins]

Drew,

I got that message if I tried to open a .BSB file. The .kap files worked fine.

Paul

[georgelewisray]

Seven Seas Cruising Forum has a thread going OLPC for navigation.

SSCA Discussion Board :: View topic - The OLPC computer for cruisers?

[phiggins]

I finally figured out how to make the Mariner program see my GPS which was connected to the XO via a USB serial cable.

If you bring up Mariner and there is nothing in the Serial port dropdown list. Do this:
stop Mariner then create a new file:

/home/olpc/Mariner/jre/linux/lib/ext/gnu.io.rxtx.properties

and add this line:

gnu.io.rxtx.SerialPorts=/dev/ttyUSB0:/dev/ttyUSB1:

save the file.

Restart Mariner

The above statement will tell the RXTXCommDriver.java explicity which ports to look for the GPS.

Paul

[agkirk]

Paul, I have attempted to load the Navgator Marine SW on my OLPC and ran into a problem I can't solve. I was not able to retrieve the .gz file using wget so I transfered the .gz file using a PC and USB drive to my OLPC SD, then TAR'e the file., on the SD in its own folder It appeared to unpack but with two errors at the end saying Canot create symlink to /libjsig.so etc. I tried to execute the program and it seemed too run i.e. a compass rose graphic showed then the app halted. Not being a Linux user, I don't know how to execute the app from the terminal. Mariner/mariner does not seem to work from the top level shell or from the SD card. Also, when you say olpc is "your" userid, is there more to that than just using "olpc".

Thanks,

Alan

[hellosailor]

Bear in mind that inverters tend to be inefficient except at full load. I don't recall the exact numbers but running a 175W inverter for a (10v x 2a =) 20watt device would probably be very inefficient. If the XO can run off raw ships' battery power I wouldn't be surprised to see numbers showing way less power used.

Likewise Bluetooth and Wifi both have provisions for automatically adjusting their transmit power, although I have no idea of the maximum power available to the radios in those two computers. 25-100mW seems typical for laptops but 600mW is available if they choose to use the hardware for it.

[phiggins]

Alan,

I also decided to put the Mariner program on an SD card and I happened to read the install instructions and discovered my original instructions may not be completely correct. Below are the instructions I now use.
to install Mariner from an SD card:

cd ~ ....this will take to your home directory.
pwd ....this will tell you path to your home directory which should be
/home/olpc use this in gzip instruction below.
dir /media ....this will show the name of the SD card mine was KODAK
su - ....this will make you superman (well super user anyway)
cd /media/KODAK ....this puts you in the SD cards directory.

gzip -dc SetupMariner-Linux-3_1_1.tar.gz | (cd /home/olpc; tar xvf -)

The command above will install mariner in your home directory. Once complete issue:
exit .... this will go back to your user id.
cd ~ ....this will put you in your home directory.
dir ....this show you all the directories and files in the home directory
You should see one called Mariner.
If you haven't already, update the lock files. See previous post regarding doing that.

Mariner/mariner ....this will start Mariner.

I believe everyone's user id will be olpc unless you added a new one so don't worry about it.

paul

[phiggins]

I decided I should have some way to reinstall the complete operating system if something happens when I'm far away from the internet. On Windows I would dig out the XP CD and reboot from it. On the XO computer you can create a boot SD card. See the instructions at:

Activated Upgrade - OLPC

I happened to have a 512M SD card so I cleaned it off and installed the files mentioned. I also added another text file with those instructions plus instructions how to reinstall everything I had on before. And I also put any critical programs like the Mariner .gz install file on the SD.

I actually tried it to make sure it works and it did. Its a good way to clean up the flash drive.

Beware: if you do it you will lose everything you had installed previously!

Paul

[phiggins]

HelloSailor, yes running the XO off of the inverter isn't very efficient. When I was testing the XO on the boat plugged into the inverter, the inverter itself was drawing 1.1Amps.

From the hardware specs for the XO it says:

DC power: 6mm (1.65mm center pin) connector; 11 to 18 V input usable, –32 to +40V input tolerated; power draw limited to 15W

So it may run perfectly fine if I were to connect it directly to ship's battery. Just have to find a suitable plug.

Paul

[hellosailor]

Paul-
The infinite assortment of plugs seems intended solely to confound and confuse us, doesn't it?<G>

It sounds like you have what is properly called a "coaxial power connector" and I'm guessing 6mm is the overall length of the plug? The 1.65mm center pin also defines the width of the plug, this sounds like a fairly common 12v 2A type power range/size. Radio Shack will probably have one for $5.95, the internet electronics shops will probably sell you two for a buck less--before shipping charges.
You could probably get a *small* 12V "exit light" aka UPS or alarm battery to run that for a long time, and just recharge that off the ships' power too.
All Electronics Corp - Parts, Supplies and Components one of the many reasonable surplus places on the web. I think their shipping is a flat $7? for your first $100 worth of order. Larger shops like Digi-Key Corporation - USA Home Page are way larger, new parts, but something like a $5 handling fee if your order is under $25, plus shipping by weight.

[RBEmerson]

Originally Posted by drewc

Paul, thanks so much for documenting these steps. I followed exactly and was able to get the app going with a few minor tweaks, most importantly a REBOOT after editing the uucp and lock entries. I have also noticed that upon exiting the Navgator app I get a "javax.sound.sampled.LineUnvailableException" regarding something to do with a "getClip" request that fails due to "little-endian not supported"...I suspect I have not set up some kind of sound resource or capability. While it doesn't seem to bother the app itself it is curious.
One final question (I hope!)...were you successful in locating a USB-Serial adapter for your GPS that works with the XO drivers? Thanks again for your help!

Thanks, Drew

Howdy - I was pointed to this topic from the related topic on the SSCA forum. The message about little-endian non-support is nothing you can do anything about. It refers to the fact that a "word" of data (made of two bytes) is swapped, so that the least significant byte (the "little end") comes first in the word, as opposed to being "big-endian" (three guesses what happens there... ) and it's tied to nature of your PC.

In general, sad to say, NavGator isn't the best computer citizen I've ever met. There's far too much "my way or the highway" in the serial port processing and, as you discovered, the sound handling.

[scotte]

That is a bit strange considering Intel processors are little-endian, and while I have no idea if the XO uses an x86 architecture, it's pretty darn common!