Help / FAQ

[Hubert_mar]

Hello


thanks for the tip

I checked so the gps goes in dev/ttyUSB0. but still the same error message.

Do you have an idea of where the problem could be?
should I uninstall opencpn and try the whole thing from scratch?


Best

Hubert

[nohal]

Hubert...
Uninstalling OpenCPN will not help you with anything.
Make sure you can connect to the port using eg.

screen /dev/ttyUSB0

under the same user you use to run OpenCPN. Then make sure you exited from the screen (normally Ctrl-A, K), then start OpenCPN and make sure the settings are correct and everything should work. If it still does not, look at your logfile and if the problem is not clear from it, try to post it here.
I would personally fix GPSd as it will allow you to use several applications with the GPS at the same time.

Pavel

[bcn]

Originally Posted by nohal

I would personally fix GPSd as it will allow you to use several applications with the GPS at the same time.

Pavel

Another point to check: be sure that no other application is connecting to the serial port. Serial ports do not allow multiple connections.

[Hubert_mar]

Thanks for the tips!


After screen /dev/ttyUSB0 in the terminal, I have an endless arrival of "xxxxx ff ss" and other characters, which I assume is the 'screen' interpretation of the gps signal (since I have removed gpsd)


running the commands:

$gedit `echo $HOME/.opencpn/opencpn.conf`
and
gedit `echo $HOME/opencpn.log`

however both opencpn.log and opencpn.conf appears to be empty in the text editor. I suppose that is not normal?



I will retry with gpsd but I don't have any other app using the GPS.

[nohal]

You should definitely not see anything like "xxxxxx ff ss", but normal NMEA sentences, like "$GPRMC,194459.00,A,3748.56183,N,12226.93694,W,6.5 71,137.98,160712,,,A*7F". There is nothing to be interpreted by screen.
The reason for you to see garbage may be that your GPS is switched to binary mode (= unusable with OpenCPN unless switched to NMEA) or you are using wrong baud rate.
You may try to start screen with

screen /dev/ttyUSB0 baud_rate

where baud_rate may be pretty much anything from 110, 150, 300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 (The bold ones are much more likely)

The config file and logfile are sure not empty, unless you did something very bad to them.

[Hubert_mar]

I re installed the gpsd package (cmd

$ sudo apt-get install gpsd gpsd-clients

then I checked with

$ gpsmon /dev/ttyUSB0

and I have the result in the attached image



but when I run the cmd

$ xgps /dev/ttyUSB0

I have the following error : TypeError: Couldn't find foreign struct converter for 'cairo.Context'

or when I try with

 $ cgps /dev/ttyUSB0

I have : {"class":"VERSION","release":"3.17","rev":"3.17"," proto_major":3,"proto_minor":1
2}
{"class":"ERROR","message":"No such device as /dev/ttyUSB0"}



So the problem is not with opencpn but with my gps, right?


I read that it could be a kernel issue
using

$ lsmod

Module Size Used by
pps_ldisc 16384 0
pl2303 20480 0
usbserial 45056 1 pl2303



pl2303 is the the changing line I get when I type

lsusb

before/after plugging the gps
"Bus 001 Device 017: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port"



I don't know what I should do after?

Sorry for the troubles, i feel inda stupid...

[nohal]

Is gpsd actually running? Given you can connect to the port using gpsmon, I would say it was not started by D-Bus when you connected the GPS.
Both cgps and xgps and are gpsd clients and you are starting them incorrectly - they need a gpsd server, not a device as a parameter (see https://www.systutorials.com/docs/linux/man/1-cgps/)

You may check gpsd by

systemctl status gpsd.service

If not running, start it using

systemctl start gpsd.service

and then try if cgps works using

cgps localhost

[Hubert_mar]

after rebooting and unplugging the gps, I used the "status" cmd to check gpsd was not working.
after connecting the gps, I used the "status" cmd and gpsd was not running so I started it, and got the following message which I think is positive.

gpsd.service - GPS (Global Positioning System) Daemon
Loaded: loaded (/lib/systemd/system/gpsd.service; indirect; vendor preset: enabled)
Active: active (running) since Fri 2019-04-05 08:19:12 CEST; 8min ago
Process: 2874 ExecStart=/usr/sbin/gpsd $GPSD_OPTIONS $DEVICES (code=exited, status=0/SUCCESS)
Main PID: 2875 (gpsd)
Tasks: 1 (limit: 4540)
CGroup: /system.slice/gpsd.service
└─2875 /usr/sbin/gpsd

avril 05 08:19:12 hubert-UX31E systemd[1]: Starting GPS (Global Positioning System) Daemon...
avril 05 08:19:12 hubert-UX31E systemd[1]: Started GPS (Global Positioning System) Daemon.

but with

cgps localhost

all I have, after a while, is "GPS timeout".


gpsmon is still ok. Should i not be able to use it while gpsd is running?

[nohal]

Originally Posted by Hubert_mar

after rebooting and unplugging the gps, I used the "status" cmd to check gpsd was not working.
after connecting the gps, I used the "status" cmd and gpsd was not running so I started it, and got the following message which I think is positive.




but with

cgps localhost

all I have, after a while, is "GPS timeout".


gpsmon is still ok. Should i not be able to use it while gpsd is running?

Only one process can acquire the serial device at any given moment. Once it is gpsd, nothing else is able to communicate with /dev/ttyUSB0, when it is gpsmon, it is only gpsmon, when it is OpenCPN, it is OpenCPN and nothing else. First one comes, first one rules.
What you describe means that gpsd is not working with your GPS at all, hard to say why as it simply should be invoked by udev through D-Bus as soon as the device is connected.

Anyway, let's try to help it a little.

Make sure your user is in the dialout group

sudo adduser $USER dialout

Log out and back in after that

Edit /etc/default/gpsd and change DEVICES="" to DEVICES="/dev/ttyUSB0"

restart (or start) gpsd

Does it work now?

[sy_gilana]

Last resort question.


Where is the "Auto Follow" feature on O5.0?

[nohal]

Originally Posted by sy_gilana

Last resort question.


Where is the "Auto Follow" feature on O5.0?

And much improved compared to previous versions, read https://opencpn.org/OpenCPN/about/ver500.html

[sy_gilana]

Thanks Nohal,
I thought it was that, but it does not center the screen on the boat when green, BUT it does follow.


Now that I have played with it I understand it and the effects of Look Ahead. (Which I never used).

Its a much improved philosophy. Thank you.

[Hubert_mar]

Thanks Nohal!!!


I edited the file and restarted the opencpn connexion! It worked perfectly and still does after a reboot!
you rock!


(I will duplicate the solution to the french ubuntu forum!)


Best

Hubert

[transmitterdan]

To put the ship in screen center turn on auto-follow and then left click on the ship. It will move to screen center.

[OlleH]

Maybe someone have seen this problem before but I can not find anything about it.
I am running an RPI B3+ with a normal GPS puck that works just fine and allways have a close to correct positioning on the sea chart. My VHF is connected thru an USB dongle making the DSC work on the VHF. I allways get a correct stamp and possition when I turn it on but there it stops, It does not update. I have an auto pilot also connected and thru the same USB(NMEA) dongle. It works just fine following a highway.
Today I put up the GPS watch on the daschboard an it worked the same way. It recieved a correct time at start but did not update after that.
What is wrong ?