No GPS Communication Ubuntu 12.10
No GPS Communication Ubuntu 12.10
February 03, 2013 01:22PM
I had PolarNavy and PolarCOM working okay on Ubuntu 12.04, but have now reinstalled on a new laptop running Ubuntu 12.10 without success. And, I seem unable even to get it working on my old laptop either.

Both are installed and run okay; however PolarCOM never gets the expected data from the GPS.

The GPS that I am using is the recommended BU-353. On insertion it picks up ttyUSB0 without an issue.

I have tested with GPSD and I am able to read data from the device using the gpspipe command, and the following output is typical:

{"class":"VERSION","release":"3.6","rev":"3.6","proto_major":3,"proto_minor":7}
{"class":"DEVICES","devices":[{"class":"DEVICE","path":"/dev/ttyUSB0","activated":"2013-02-03T17:58:37.072Z","flags":1,"driver":"SiRF binary","subtype":"GSW3.5.0_3.5.00.00-SDK-3EP2.01 ","native":1,"bps":4800,"parity":"N","stopbits":1,"cycle":1.00},{"class":"DEVICE","path":"/dev/ttyUSB1"}]}
{"class":"WATCH","enable":true,"json":true,"nmea":false,"raw":0,"scaled":false,"timing":false}
{"class":"TPV","tag":"MID2","device":"/dev/ttyUSB0","mode":3,"time":"2013-02-03T17:58:36.000Z","ept":0.005,"lat":51.239517127,"lon":-0.522090080,"alt":79.494,"epx":9.674,"epy":14.109,"epv":36.517,"track":359.3177,"speed":0.097,"climb":-0.078,"eps":28.50}
{"class":"TPV","tag":"MID2","device":"/dev/ttyUSB0","mode":3,"time":"2013-02-03T17:58:37.000Z","ept":0.005,"lat":51.239517192,"lon":-0.522075758,"alt":79.489,"epx":9.674,"epy":14.109,"epv":36.517,"track":51.5329,"speed":0.316,"climb":-0.158,"eps":28.22}

I have checked the PolarCOM settings and it just sits on Detecting indefinitely. I have unchecked Autodetect and have specified /dev/ttyUSB0 manually, whereon it changes to status Running. My understanding is that that means it is working and yet still I have "No GPS Data" displayed.

I have checked what programs have ttyUSB0 open, and the only one is PolarCOM.bin with the correct PID number.

I have noticed a problem in Ubuntu 12.10 that I get a large number of errors when running PolarCOM, e.g.

`menu_proxy_module_load': ./PolarCOM.bin: undefined symbol: menu_proxy_module_load
(PolarCOM.bin:4487): Gtk-WARNING **: Failed to load type module: (null)

I fixed that by adding the following to the /opt/polarcom/bin/PolarCOM script:

export UBUNTU_MENUPROXY=0

This leaves just one error when running PolarCOM:

Gtk-Message: Failed to load module "overlay-scrollbar"

Which I gather is related to the dreadful new Ubuntu scrollbars. Hate them though I do, I doubt it is that stopping the GPS from working!

I would be grateful for any advice as I am at a loss at this stage. Perhaps PolarCOM has a debug mode that I could try?

Thank you,

Chris Roberts
Re: No GPS Communication Ubuntu 12.10
February 04, 2013 03:25AM
- What do you see in NMEA Terminal in PolarCOM?

- What do you see if you use screen command line utility to open /dev/ttyUSB0 (you can do so with the following command: screen /dev/ttyUSB0 4800

--
Polar Navy Support
Re: No GPS Communication Ubuntu 12.10
February 04, 2013 08:29AM
Polar Navy Support Wrote:
-------------------------------------------------------
> - What do you see in NMEA Terminal in PolarCOM?

Does that option exist in the Linux version of PolarCOM?

> - What do you see if you use screen command line
> utility to open /dev/ttyUSB0 (you can do so with
> the following command: screen /dev/ttyUSB0 4800

Not sure what you are expecting, but I am just seeing a stream of unicode characters, but as far as that goes it looks healthy.

--
Chris Roberts
Re: No GPS Communication Ubuntu 12.10
February 04, 2013 09:33AM
It seems that the problem is that the Linux gpsd daemon automatically switches the GPS receiver into SIRF III binary mode - hence the unicode garbage.

To resolve this issue I checked that gpsd was not running (it wasn't). (In Ubuntu 12.10 stopping the gpsd daemon does not work, so the only option is to "killall gpsd".)

To switch the GPS into NMEA you type:

$ gpsctl -f -n /dev/ttyUSB0

You may also need to configure the serial port:

$ stty -F /dev/ttyUSB0 ispeed 4800

To check that has worked:

$ screen /dev/ttyUSB0 4800

And you should see the ASCII NMEA sentences being returned.

Lastly, I reconfigured gpsd to read-only mode, but typing:

$ sudo dpkg-reconfigure gpsd

And at the point it requests switches, I added "-b" (Broken Device Safety Mode), otherwise known as read-only mode.

Thank you for your help, seeing the binary output from screen was the clue I needed.

Kind regards,

--
Chris Roberts
Re: No GPS Communication Ubuntu 12.10
February 05, 2013 10:51AM
Good to know it worked - and useful information for other users who might experience the same issue!

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Polar Navy Support
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