OpenCPN General

[Nicky Barker]

Awesome!! Thank you Dsanduril. The manual fix in the command line worked. We'll look at installing OpenPlotter and also a real-time clock but, in the meantime, we're up and running, which is great news.

[LeaseOnLife]

Originally Posted by Nicky Barker

Awesome!! Thank you Dsanduril. The manual fix in the command line worked. We'll look at installing OpenPlotter and also a real-time clock but, in the meantime, we're up and running, which is great news.

Another more automated option: You can run gpsd and ntpd on the PI. GPS serial input to gpsd, that feeds opencpn the gps position as well as the gps time to ntpd, which does synchronize the clock on the PI. This works well enough with USB-serial connected GPS receivers to be accurate within a second. It took me a while to get ntp working, the trick in /etc/ntp.conf was the following lines:

# GPS Serial data reference, 
server 127.127.28.0 minpoll 4 maxpoll 4 iburst prefer
fudge 127.127.28.0 time1 0.420 stratum 1 refid GPS0
# no pps available here, no 127.127.28.1

the USB-gps 'jitters' a bit, it will take ntp a while to accept the date/time, but it will since it is the only clock source:

 ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 *SHM(0)          .GPS0.           1 l   13   16  377    0.000    5.137   3.711

the star at the before SHM indicates a valid time source.


Cheers!

[Nicky Barker]

Hi LeaseofLife. Thank you for this. However, you are assuming a level of knowledge that I just don't have! Do I just type in your code:

# GPS Serial data reference,
server 127.127.28.0 minpoll 4 maxpoll 4 iburst prefer
fudge 127.127.28.0 time1 0.420 stratum 1 refid GPS0
# no pps available here, no 127.127.28.1

at the ~$:

or do I need to upload gpsd and ntpd programmes to the Raspberry Pi first?

[Dsanduril]

Do you have a GPS connected directly to the Pi? Or do you get GPS data over NMEA? If the former then you can install gpsd and have it read the GPS information and then forward it to OpenCPN.

If the latter then you will need to configure OpenCPN with a new network connection of type gpsd to re-transmit the GPS info to the system.

So, which way do you have things set up?

[Nicky Barker]

Hi Dsanduril, We have a multiplexer that takes the GPS and AIS feeds and sends them to the Raspberry Pi via the Pi's USB 3.0 port. On the OpenCPN v5.0.0 Options-Connections page this shows as Serial type, input, NMEA 0183 protocol, serial port /dev/ttyUSB0. So, I assume that this means we get the GPS data over NMEA. Assuming this is correct, how do I reconfigure OpenCPN with a gpsd network connection?

[LeaseOnLife]

sudo apt-get install gpsd

:-)


the default options for gpsd should autodetect your NMEA input via USB, but I like to force/fix that to a specific input


The lines I typed above need to go into the configuration file for ntpd, in /etc/ntp.conf


Then ntpd can read from gpsd via shared memory and gets the time that way.

[Dsanduril]

Hmm, I'd have to spend some time playing with this. I had thought O could output on gpsd, but it can only take input.

If the GPS was connected directly to the Pi you could then connect that to gpsd, and then connect O to gpsd to get the position information.

But, with the multiplexer adding AIS info I don't think that will work because the port would be captured by gpsd and I don't think gpsd would forward the AIS.

As I said, not a particular configuration I've tried so I'd have to play at it, maybe LoL can provide some more insight.

[Nicky Barker]

Thank you both Dsanduril and LeaseOnLife. We tried

sudo apt-get install gpsd

and our system said that the most up-to-date was already installed (though, having searched we can't see it anywhere in the file structure). Similarly, we can't find /etc/ntp.conf in the file structure. So, for the time being, we'll work on manually updating the time when we switch on the Raspberry Pi, which will be good enough for our needs. When we have a good internet connection we may revisit the issue. Thank you for your help.

[LeaseOnLife]

Originally Posted by Dsanduril

...

But, with the multiplexer adding AIS info I don't think that will work because the port would be captured by gpsd and I don't think gpsd would forward the AIS.
...

gpsd does forward AIS messages too!

https://gpsd.gitlab.io/gpsd/

[Dsanduril]

etc should be way back at the root of your filesystem. You're likely starting at the user directory (the Linux default), so from a command line:

cd /etc

should get you there (if you're using a GUI sometimes getting back lower than the user directory is hard to find, but it is there somewhere).

You don't actually even have to change to that directory, you can call the file from wherever you are. Run an editor to change the config file. Depends on what editor you have.

sudo nano /etc/ntp.conf
or
sudo vi /etc/ntp.conf

I use sudo because that usually provides write privileges to /etc. I prefer nano, but vi is probably more prevalent in default installs. Then put in the lines shown by LoL, your default file probably looks something like this:

# You do need to talk to an NTP server or two (or three).
#server ntp.your-provider.example
server 127.127.28.0 minpoll 4 maxpoll 4 iburst prefer
fudge 127.127.28.0 time1 0.420 stratum 1 refid GPS0
# pool.ntp.org maps to about 1000 low-stratum NTP servers. Your server will
# pick a different set every time it starts up. Please consider joining the
# pool: <http://www.pool.ntp.org/join.html>
pool 0.debian.pool.ntp.org iburst
pool 1.debian.pool.ntp.org iburst
pool 2.debian.pool.ntp.org iburst
pool 3.debian.pool.ntp.org iburst

if using vi then

ESC
:wq

to save and quit

nano

Ctrl-o (letter 'o', not zero)
Ctrl-x

you'll probably still need to start gpsd/configure it to run on startup. That depends on how your initial system was set up.

To check if gpsd is running:

systemctl status gpsd

[LeaseOnLife]

Originally Posted by Nicky Barker

Thank you both Dsanduril and LeaseOnLife. We tried

sudo apt-get install gpsd

and our system said that the most up-to-date was already installed (though, having searched we can't see it anywhere in the file structure). Similarly, we can't find /etc/ntp.conf in the file structure. So, for the time being, we'll work on manually updating the time when we switch on the Raspberry Pi, which will be good enough for our needs. When we have a good internet connection we may revisit the issue. Thank you for your help.

don't give up yet!


ps ax |grep gpsd



that should tell whether gpsd is running.



if it is, the try the command



cgps


that then should show your current position and several messages scrolling thru

[Dsanduril]

Originally Posted by LeaseOnLife

gpsd does forward AIS messages too!

https://gpsd.gitlab.io/gpsd/

Cool! Thanks for that

[MalteseFalcon]

I am running OpenCPN ver 5.0 with CM93-2011 charts and I need help with what shows up on the vector charts. At the moment I can only see depths and light beacons, I do not see any country names, harbour names or city names. I remember on previous versions this was all there using the same charts.
Advice, please

[Reefmagnet]

Originally Posted by MalteseFalcon

I am running OpenCPN ver 5.0 with CM93-2011 charts and I need help with what shows up on the vector charts. At the moment I can only see depths and light beacons, I do not see any country names, harbour names or city names. I remember on previous versions this was all there using the same charts.
Advice, please

Your get this clicking the 3 horizontal bars icon at the lower right of the chart window and selecting the "Show Text" option under "Vector Charts". It isn't selected by default.

[moseriw]

Same with Keyboard T
Me too... always searching... I do always forget it....


Maybe it would be better to change the defaults....