AvNav - navigation in the browser

[wellenvogel02]

Ok, thanks first for the reports.
Seems to be an issue with chrome in some versions being unable to render the background SVGs.
We will further investigate on this.

[wellenvogel02]

Originally Posted by Kukel

I'm sure it's possible! The question is: can I have AvNav generating RMC and somehow avoid this RMC to end up in the SignalK data stream. SignalK already gets RMC from the GPS mouse.

The reason I don't send RMC from the GPS mouse to the repeater is that the repeater doesn't "like" the mouse's RMC and fails to show SOG/COG. If I let OpenCPN send RMC, the repeater shows all the right data.
Also, when I have OpenCPN generate RMC, there is no data loop, so I wonder why it's there if I do the same in AvNav (send RMB and RMC on UDP connection)

Not sure what you really would like to do. AvNav normally will not generate RMC at all (except for special conditions from canboat n2k data).
Basically it will send all NMEA it has to all outputs unless you use a filter or a blacklist at the output.
For the openplotter set up (if you did not change things) there should be a SocketReader (named signalk) that will get all NMEA from signalk.

<AVNSocketReader port="10110" host="localhost" filter="^$RMB" name="signalk"/>

Additionally there is a socket writer

<AVNSocketWriter port="28628" maxDevices="5" blackList="signalk" filter="" read="true" minTime="50" name="tosignalk"/>

That will send NMEA data coming in from anything else then from the SignalK connection back to SignalK. This exactly should be the RMB created by AvNav itself. And the reader has a filter that prevents RMB from coming back from SK to AvNav.
So what would you like to send out to your repeater - and on which channel?

As AvNav will not generate an RMC by it's own you can only send out the one that already comes in. Or let Sk generate an RMC (in this case you potentially would have more then one...).

For finally sending out you can either use AvNav or SignalK.
If you would like to prevent the RMC coming from your GPS passing thru - maybe you could filter this at the input when it comes in to SignalK and rely on the remaining sentences to get the position data. And let the Sk to nmea0183 plugin generate an RMC.

What is the physical connection to your repeater? NMEA0183?

[Kukel]

I realise that this is a very specific situation, so thank you for bearing with me.
The repeater is connected with a RS232/USB interface to the RPi.
It needs NMEA sentences RMB and RMC.

In SignalK there's a serial port configured for the repeater.

What I started with:

To this serial port I sent the incoming data from the GPS mouse, and the outgoing data from my navigation app, so OpenCPN or AvNav. I have configured an UDP port in both sending RMB.

With the described setup, the repeater receives RMC from the mouse and RMB from the navigation app, and all should be fine. However, in practice, the GPS repeater display did not show SOG and COG values. Apparently, it didn't understand something in the GPS mouse's RMC.

By experimenting, I found that if I filtered RMC out of the GPS mouse data that is sent to the serial port (with the NMEA0183 filter&forward plugin in SignalK) and let OpenCPN send RMC to an UDP port that was then forwarded to the repeater display, everything worked fine.

So I tried to duplicate this setup with AvNav. However, this creates a loop. SignalK shows that instead of two messages per second, over 200 are sent by AvNav.

Now if I understand your post correctly, I could send RMC from AvNav to the UDP Port, and filter RMC on the SocketWriter so it doesn't get sent back to SignalK. That way, I could avoid the loop. Is that right?

[wellenvogel02]

Not sure what you do with the UDP port...
Do you send data with a udp writer from AvNav to SignalK?
This would for sure create a loop.
The SocketWriter is not in the game at this point. As I wrote - it will not send data to SK it receives with the SocketReader from SK 10110...
Most probably I still do not understand what you would like to do.
I miss the relatio between sending out data via udp and the serial output.
If you need to pass the GPS data through either AvNav or something else to maybe filter away some garbage in the sentences you could try to let the GPS mouse come in in AvNav instead of SK.
No additional connections beside the reader for it in AvNav...

[Moo]

I am looking for guidance on what AVNav does with the network settings on the raspberry pi. As soon as I install AVNav I loose control of the network connections, currently I can't open the signalk plugin either. Dhcpcd.conf seems to have been messed with along with netstat stuff etc..

Anyway all I get in the gui network icon are 2 red X and a message on hover that says can't access dhcpd. The SignalK plugin doesn't load either but that could be something else

I don't want to use the AVNav image for various reasons. I also want to keep full control of network settings.

If config shows the interfaces and AVNav accesses the ethernet port for Openstreetmap tiles etc..

I have a plain vanilla default raspbian install .. it works great until I install AVnav; which then takes over the network setup... I can't figure it despite lots of ferreting around, I think it might be something to do with network interface drivers but not sure.

Any pointers please. I'm heading out on a 2 week cruise this weekend and looking to get it sitting stable by then. It was ok but I feel the latest updates might have been the culprit.

Cheers
Chris

P.S. it seems to do something similar when part of openotter.

[wellenvogel02]

It depends on what you install.
If you are running on a plain system and want to install avnav using packages you should NOT install the avnav-raspixxxx package.
This is intended for our headless images and really takes over the network config.
Just install the avnav package and the plugins you would like to get.
See the hints at https://www.wellenvogel.net/software...geInstallation
On Openplotter things are different - openplotter handles the network - AvNav is not in the game there.

[Kukel]

Originally Posted by wellenvogel02

Not sure what you do with the UDP port...
Do you send data with a udp writer from AvNav to SignalK?
This would for sure create a loop.

Yes, that's what I do, sorry if I don't explain myself very clearly. So an UDP port is not the right way to get RMC from AvNav to the serial port. Then the fact that this does work with OpenCPN is probably mere chance...

The SocketWriter is not in the game at this point. As I wrote - it will not send data to SK it receives with the SocketReader from SK 10110...
Most probably I still do not understand what you would like to do.
I miss the relatio between sending out data via udp and the serial output.
If you need to pass the GPS data through either AvNav or something else to maybe filter away some garbage in the sentences you could try to let the GPS mouse come in in AvNav instead of SK.
No additional connections beside the reader for it in AvNav...

Is there a direct way to send data from AvNav to a serial port without involving SignalK?

If not, letting the GPS mouse data come in in AvNav and then send RMB and RMC through to SignalK sounds like a good option, I will try that out.

[BlackSea]

Originally Posted by Kukel

Is there a direct way to send data from AvNav to a serial port without involving SignalK?

for example

<AVNSerialWriter name="ttyS2" port="/dev/ttyS2" baud="4800" combined="true"/>

[wellenvogel02]

And you can directly do this in the UI...
Just use the "+" button on the server/status page (the one with the bar chart icon).

In principle you could also enable the USB serial handling (one of AvNav's power features...) that is currently disabled in the Openplotter set up.
That would allow you to control all (serial) devices connected via USB.
But then you would need to be careful about SignalK and AvNav trying to access the same devices..

[wellenvogel02]

Originally Posted by Kukel

So an UDP port is not the right way to get RMC from AvNav to the serial port. Then the fact that this does work with OpenCPN is probably mere chance...

Basically it would make no sense as the connection is there any way with the SocketWriter (as I explained).
But the problem is to prevent the looping.
Unfortunately AvNav has no chance to see if some NMEA being received from SignalK has originally being sent by it's own...

Not sure if there would be a chance to configure a separate data path trough signalK (e.g. UdpWriter or SocketWriter from AvNav -> SignalK separate connection->SignalK serialout) - just to prevent this data going back to AvNav via 10110. I guess it should be possible using the event name features of signalK.
But as already discussed - configuring the serial in or out in AvNav could be much easier.

[wellenvogel02]

For the icon issue:
I just uploaded a new demo - would be interesting if someone could try if this one works with one of the devices that failed before.
It's hard for me to test as I do not have the issue at all..
direct link - added some number to force reload.

[BlackSea]

Originally Posted by wellenvogel02

would be interesting if someone could try if this one works with one of the devices that failed before.

Android 4.4, Chrome 81 - passed
Android 7.1 Chrome 89 - passed
Android 10 Chrome 90 - passed

[Moo]

Thanks for the networking tips. not installingthe RPi specific package leaves me with a network

I have now run into another problem. A gemf chart file built on Windows of the NZ raster charts ends up in two parts, the second being xxxxx.gemf-1

When I put the two files in the charts directory on the pi. They do no load and an error is thrown:

2021-05-01 13:52:40,377-499-796-ChartHandler-INFO-file BSB_ROOT-1.gemf filtered out
2021-05-01 13:52:45,380-499-796-ChartHandler-INFO-trying to add file BSB_ROOT-1.gemf
2021-05-01 13:52:45,381-499-796-ChartHandler-ERROR-error opening chart BSB_ROOT-1.gemf:Traceback (most recent call last):
File "/usr/lib/avnav/server/handler/charthandler.py", line 368, in onItemAdd
itemDescription.setChart(chart,self.getIntParam('upzoom'))
File "/usr/lib/avnav/server/handler/charthandler.py", line 180, in setChart
chart.open()
File "/usr/lib/avnav/server/gemf_reader.py", line 66, in open
raise Exception("file %s: invalid gemf version detected %d (expected 4)" %(self.filename,version))
Exception: file /var/lib/avnav/charts/BSB_ROOT-1.gemf: invalid gemf version detected -1991225785 (expected 4)

2021-05-01 13:52:45,381-499-796-ChartHandler-INFO-file BSB_ROOT-1.gemf filtered out

Seems to be an incompatibility between what is generated on the windows machine with what the Pi is trying to read?

Cheers
Chris

[Moo]

Originally Posted by wellenvogel02

For the icon issue:
I just uploaded a new demo - would be interesting if someone could try if this one works with one of the devices that failed before.

It Works on Chrome on my Galaxy A52 now. There is brief but noticeable blink on the affected icons as they first appear blank and then half a second later reload. That is using your test link; of course that might not even be perceptible on a local server.

Chris

[wellenvogel02]

Originally Posted by Moo

I have now run into another problem. A gemf chart file built on Windows of the NZ raster charts ends up in two parts, the second being xxxxx.gemf-1

Did you rename the file when uploading?
The name for the second part should be xxxx.gemf-1 but you have now BSB_ROOT-1.gemf.
This will not work.
Unfortunately you cannot upload multipart gemfs directly in the UI..
How did you run the conversion on Windows?
Directly from the UI?