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[mhorwitz]

I am pretty handy and can deal with most mechanical issues on my boat but when it comes to computer scale fine wiring jobs I fall short of the required skills. In any case long story short, I don't inderstand how to wire the amphenol connector required to connect my Garmin radar to my opencpn computer. I've examined the drawings provided in the GRadar.doc but still don't understand how the connector should be wired. Perhaps someone can take a photo of an existing wired connector or provide "wiring an amphenol connector for dummies" level instructions.

Thanks in advance
SV Vagabond

[rgleason]

@mhorwitz
See attached from bdbcat dated 8/30/2016.
Search on the forum here for that document around that time.
One of the threads has a bigger picture and clearer diagram if this one is not good enough for you.

Please post that link here, I need it. Thanks.

[cgreen]

Hi. Does anyone know if there might be a way to simultaneously display the position of two different GPS inputs, with their NMEA data coming in on two separate com ports? One GPS input from the main boat, and a second GPS on a boat being towed, with NMEA data sent to main boat by a simple radio serial link. Maybe there is a way to configure it so that the second (towed) GPS appears as an AIS target. Not sure. Thanks in advance for any help or suggestions.

[Hakan]

cgreen..
Such an interesting task can result in lots of ideas. Not less in this brilliant forum.
First:
No - you can't view a second GPS's position in OCPN if you just transfer the GPS signal to another COM port. The result will be a jumping own ship, altering between yours and the towed's position.
Second:
What do you have on the towed boat? You can send the GPS signal but how do you do that? In some way you are to able to transmit the GPS via a radio. Please describe in details how the GPS signal is transferred. Then it's easier to suggest some kind of string adaption/manipulation to give OCPN in your boat something that can be viewed.
If the GPS signal could be transferred to a NMEA TTM message your towed fellow will show up with a AIS alike symbol and behavior. - Just an idea of plenty possible -

I've not checked the NMEA converter plugin i all details. Can it take over all what's coming in via a specific port and convert it without OCPN interference? I don't think so but - anyone -
Håkan

[mhorwitz]

Originally Posted by rgleason

@mhorwitz
See attached from bdbcat dated 8/30/2016.
Search on the forum here for that document around that time.
One of the threads has a bigger picture and clearer diagram if this one is not good enough for you.

Please post that link here, I need it. Thanks.

Thanks rgleason- got it all figured out. A key step was making sure all the network cable connections were shielded to complete the drain wire circuit. After that the scanner powered up and displayed over the navigation chart properly. Very painless installation overall.

Many thanks to all the folks who shared there skills developing the add-on.

[cgreen]

Originally Posted by Hakan

cgreen..
Such an interesting task can result in lots of ideas. Not less in this brilliant forum.
First:
No - you can't view a second GPS's position in OCPN if you just transfer the GPS signal to another COM port. The result will be a jumping own ship, altering between yours and the towed's position.
Second:
What do you have on the towed boat? You can send the GPS signal but how do you do that? In some way you are to able to transmit the GPS via a radio. Please describe in details how the GPS signal is transferred. Then it's easier to suggest some kind of string adaption/manipulation to give OCPN in your boat something that can be viewed.
If the GPS signal could be transferred to a NMEA TTM message your towed fellow will show up with a AIS alike symbol and behavior. - Just an idea of plenty possible -

I've not checked the NMEA converter plugin i all details. Can it take over all what's coming in via a specific port and convert it without OCPN interference? I don't think so but - anyone -
Håkan

The GPS from towed vessel is transferred by a simple wireless modem, pretty much a wireless serial cable. At the moment, I have it setup to output NMEA GPGGA messages every second. I have read a thread somewhere that mentioned a python script which converts incoming NMEA GGA into AIVDM (AIS) message format, which would enable showing the towed vessel as an AIS target. However, the python script only seems to listen on a TCP port, so not quite what I need. Still exploring a solution, but any ideas very welcome.

[bcn]

Originally Posted by cgreen

I have read a thread somewhere that mentioned a python script which converts incoming NMEA GGA into AIVDM (AIS) message format, which would enable showing the towed vessel as an AIS target. However, the python script only seems to listen on a TCP port, so not quite what I need. Still exploring a solution, but any ideas very welcome.

You might go back to thread you are mentioning as it discusses why the solution passes to convert to a "faked" AIS message. NMEA 0183 and the internal OCPN logic does not allow for various instances of "position".
You need to define a "target". Can be AIS or (M)ARPA. In the cited thread a solution for AIS has been presented.
You will need a multiplexer (software) which digests your (virtual) COM port with the RMC or what so ever message from your modem to fiddle it into the Python script. Or change the script so that it does listen to a serial port.
The pieces are there. So it looks quite doable.

[Hakan]

cgreen..
I think this wouldn't be to hard to find out. I'll check for a function. But not today. I'll revert.
BTW: You are running OpenCPN on Windows I suppose?
Håkan

[cgreen]

Originally Posted by bcn

You might go back to thread you are mentioning as it discusses why the solution passes to convert to a "faked" AIS message. NMEA 0183 and the internal OCPN logic does not allow for various instances of "position".
You need to define a "target". Can be AIS or (M)ARPA. In the cited thread a solution for AIS has been presented.
You will need a multiplexer (software) which digests your (virtual) COM port with the RMC or what so ever message from your modem to fiddle it into the Python script. Or change the script so that it does listen to a serial port.
The pieces are there. So it looks quite doable.

Thanks very much for the help. Yes it certainly does look doable. Will look back at the python thread and dive into this a bit further.

[Hakan]

cgreen..
I've found a little program I did a while ago and adapted it a bit. The program will read a COM port and if $xxGGA is found the position data is transferred to an IP port 10110 as a $CCTLL NMEA message and it will appear in OCPN as an ARPA target named "TOW".

If you want to test you can get it here: https://dl.dropboxusercontent.com/u/...4/GGAtoTTM.zip
Unzip to wherever it fits you and run it.
It's a small console program reading any available COM port.
Just answer "y" for the COM port where you have the towed GPS connected.
In OCPN Tools > connections add a network connection.
Set it to UDP and IP address 0.0.0.0 and port 10110. See first pict.
If everything work your Tow should appear like in the second pict.

Good luck and please ask if anything is unclear.
Håkan

[cgreen]

Originally Posted by Hakan

cgreen..
I've found a little program I did a while ago and adapted it a bit. The program will read a COM port and if $xxGGA is found the position data is transferred to an IP port 10110 as a $CCTLL NMEA message and it will appear in OCPN as an ARPA target named "TOW".

If you want to test you can get it here: https://dl.dropboxusercontent.com/u/...4/GGAtoTTM.zip
Unzip to wherever it fits you and run it.
It's a small console program reading any available COM port.
Just answer "y" for the COM port where you have the towed GPS connected.
In OCPN Tools > connections add a network connection.
Set it to UDP and IP address 0.0.0.0 and port 10110. See first pict.
If everything work your Tow should appear like in the second pict.

Good luck and please ask if anything is unclear.
Håkan

That would be a great solution. I did try your GGAtoTTM which ran ok, but I never could get it to read my NMEA $GPGGA input on com port, even though I double checked the message was coming in on chosen com port. I tried a bunch of different com parameters for the GPS output, different baud rates, stop bit, parity etc, but not sure what com parameters your program expects.

I did eventually produce an AIS target using a rather convoluted combination of serial port to UDP, then feeding it to a python script to produce AIS messaging forwarded to another UDP port, which OpenCPN could display. However, with multiple scripts involved, I will need to work a bit to make it robust. I like your solution if I can make it work. Thanks in advance if you can provide the expected com parameters. I am guessing from your notes that if the program receives data ok, it displays the NMEA string that being parsed and turned into TTM, right? Cheers, and thanks again.

[Hakan]

cgreen..
Sorry it didn't worked but let's see:
COM "normal" parameters and 4800 baud. (byte size 8, one stop, no parity)
Did the program found a usable and correct COM port and could it be opened?
(You answered "y" for the correct port, right?)
If so, was anything coming in to the program. - Press "p".

Could you get me a print of some GGA messages you receive from your GPS?

And BTW whatever the program is called it sends TLL messages to the network port 10110.

I've run it here as you can see from my pictures.

[Hakan]

cgreen..
A slightly updated version: https://dl.dropboxusercontent.com/u/...4/GGAtoTTM.zip
Before I checked if the reported position was valid (GGA pos 6 = 1 or 2) but I've changed that to only check if Lat and Long are received.
Håkan

[cgreen]

Originally Posted by Hakan

cgreen..
A slightly updated version: https://dl.dropboxusercontent.com/u/...4/GGAtoTTM.zip
Before I checked if the reported position was valid (GGA pos 6 = 1 or 2) but I've changed that to only check if Lat and Long are received.
Håkan

Thanks! Your updated version worked fine. I have also managed to get the python scripted GGA/RMC to AIS target message working ok too.

I now have another question. Is it possible in OpenCPN to setup an event (to send a message out com port maybe) when the ship gets within a certain range of a route waypoint? Even more unusual perhaps,is it possible to setup that event when an ARPA or AIS target gets within a certain range of a route waypoint? Thanks for all the help.

[Hakan]

Good to hear. Thanks for the feedback.

You've to use the Watchdog_pi(WD) and OCPN_Draw_pi(OD) plugins. In WD you can get an alarm or a message if an AIS target is inside or not longer inside a zone specified in OD. (Several options.)
Håkan