OpenCPN General

[wdkester]

Sorry, I'm still not being very clear.

I want to share the output from a COM port with two different applications on the same PC. I think I used XPORT, in the past, to do this; but it's not being maintained?

[petter5]

Originally Posted by wdkester

Sorry, I'm still not being very clear.

I want to share the output from a COM port with two different applications on the same PC. I think I used XPORT, in the past, to do this; but it's not being maintained?

Depending if your com port is rs232 or rs422. I think rs422 can have one talker and several listeners. If rs422, you can just split the cables.

Multi-Drop - Usually, up to 32 devices can be connected per port, and even more using repeaters.
Devices are distinguished by unique addresses that are assigned to each device.
For example, if you have 5 devices attached to a port, they would be addressed as units 1 to 5.
If you want to communicate to unit #1, you send a command to unit #1. All units HEAR the command, but only the addressed unit will respond.

se :https://www.omega.com/techref/das/rs-232-422-485.html

Hmm, I do some edit to this post. To share the output from one comport to two different applications on the same pc, you should definitively be able to do that by "output on this port" from the connections tab in settings. Also, if you are running linux, you should be able to use Kplex http://www.stripydog.com/kplex/

[Markus451]

This is my first post on the forums; I hope I have placed it properly.

My issue is that many of my RNC charts of BC waters use the old NAD27 chart datum, instead of NAD84 used by modern GPS's. OpenCPN documentation says that the chart datum is corrected automatically but that isn't happening. Instead, my boat position is displayed incorrectly, leading to running aground, etc. I recently had to run for shelter into an unfamiliar bay in a gale at night. That was stressful enough. No need to have inaccurate boat location on top of it!

OpenCPN correctly displays Datum: NAD27 but below it says "Warning: Chart datum may be incorrect."

Does anyone know how I can physically edit the KAP files and enter the corrections needed? Every chart legend gives the corrections needed, if only I could enter it. Thanks in advance to anyone who can help.

[Markus451]

AFTER WORKING FOR HOURS, THIS IS THE UPDATED VERSION OF POST:

My issue is that many of my RNC charts of BC waters use the old NAD27 chart datum, instead of NAD84 used by modern GPS's. OpenCPN documentation says that the chart datum is corrected automatically but that isn't happening because the datum correction line is 0,0 in these kap files. Thus my boat position is displayed incorrectly, leading to running aground, etc. I recently had to run for shelter into an unfamiliar bay in a gale at night. That was stressful enough. No need to have inaccurate boat location on top of it!

OpenCPN correctly displays Datum: NAD27 but below it says "Warning: Chart datum may be incorrect."

So far, I did indeed find out how to edit the KAP file and enter the corrections. The old line for chart datum correction looked like this: DTM/ 0.00, 0.00 (meaning no correction.) The new line I created looks like this: DTM/ 0.65, 4.75 ...referring to northing and easting.

But the original version of the chart kept displaying in OpenCPN, even when renamed and moved to a backup folder. (Interesting how OpenCPN could still find it after being renamed and moved!) And when the backup was completely removed and OpenCPN completely restarted, having removed the chart directory altogether, starting fresh and rebuilding the database, all that happened was that the amended chart disappeared from the quilt.

Anyone have any suggestions as to what to do? Why would making a change in the kap file cause it to disappear from OpenCPN?

[jackdale]

Originally Posted by Markus451

My issue is that many of my RNC charts of BC waters use the old NAD27 chart datum, instead of NAD84 used by modern GPS's. OpenCPN documentation says that the chart datum is corrected automatically but that isn't happening because the datum correction line is 0,0 in these kap files. Thus my boat position is displayed incorrectly, leading to running aground, etc. I recently had to run for shelter into an unfamiliar bay in a gale at night. That was stressful enough. No need to have inaccurate boat location on top of it!

Which chart were you using?

Most of mine are NAD 83 which is the equivalent to WGS 84, which is the GPS standard.

[Viking Sailor]

Originally Posted by Markus451

This is my first post on the forums; I hope I have placed it properly.

My issue is that many of my RNC charts of BC waters use the old NAD27 chart datum, instead of NAD84 used by modern GPS's. OpenCPN documentation says that the chart datum is corrected automatically but that isn't happening. Instead, my boat position is displayed incorrectly, leading to running aground, etc. I recently had to run for shelter into an unfamiliar bay in a gale at night. That was stressful enough. No need to have inaccurate boat location on top of it!

OpenCPN correctly displays Datum: NAD27 but below it says "Warning: Chart datum may be incorrect."

Does anyone know how I can physically edit the KAP files and enter the corrections needed? Every chart legend gives the corrections needed, if only I could enter it. Thanks in advance to anyone who can help.

Check your GPS receiver options - some receivers allow selecting other Datums as output instead of WGS84. AFAIK, OpenCPN does not have the software to convert from one Datum to another Datum.

However, it does have the ability to offset CM93 charts.

[phiggins]

I want to share the output from a COM port with two different applications on the same PC. I think I used XPORT, in the past, to do this; but it's not being maintained?

I have used GPSGate for years and its very good. You have to pay for it but its worth it.

[transmitterdan]

Originally Posted by Markus451

Anyone have any suggestions as to what to do? Why would making a change in the kap file cause it to disappear from OpenCPN?

Is there any message in the log file pertaining to this chart file? If it had problems decoding the chart file during database rebuild there might be a hint there as to what is wrong.

You might try to rebuild the texture cache although I don't think that should be the problem.

[wdkester]

Originally Posted by phiggins

I have used GPSGate for years and its very good. You have to pay for it but its worth it.

Thanks,

They seem to have a free version for 1 physical port to 2 virtual ports. I'm giving it a try.

[RhythmDoctor]

Originally Posted by wdkester

Thanks,

They seem to have a free version for 1 physical port to 2 virtual ports. I'm giving it a try.

In years past I used XPort, but it's now problematic because on newer machines with UEFI Secure Boot, you need to disable the security features. Also, I think it's 32 bit only. So it's really obsolete.

I've also used PolarCOM and GPSGate free version in the past.

But I stopped using all that stuff once OpenCPN implemented its retransmission via IP port. As long as your other apps can receive data over IP port (localhost if it's within the same machine), just have O take in the COM port and multicast it out to the other apps and/or computers/devices.

Nowadays I routinely multicast back to my boat's router on UDP, and just have my phones, iPad, etc. pick up the nav data from that. Making OpenCPN the central hub of all your data is a very clean way to do it, if you have OpenCPN running all the time anyway.

[rgleason]

RDr
Is a router neccessary? I've never done this, but can't the computer wifi act as the router to the androids and ipads?

[RhythmDoctor]

Originally Posted by rgleason

RDr
Is a router neccessary? I've never done this, but can't the computer wifi act as the router to the androids and ipads?

In general, Windows can set up an ad hoc network, in which the PC can act as if it is a router. I am not sure if Windows Basic/Home editions do this. You might need Business/Enterprise/Premium versions. Also you've got 7/8.1/10 versions, all with different subsets of the overall feature set. So I just don't know.

But regardless, Android refuses to connect to Windows ad hoc networks. This is done for security reasons. I suspect that if you root your device, someone probably has a hack that allows connection to ad hoc networks. But in my case I already have two routers on my boat (one for for Seatalk conversion, another to distribute high-gain Wifi antenna reception), so I just distribute using one of the routers. You can get a perfectly functional, low power, tiny router for around $20, so no reason not to have your data always multicasting for anyone on the boat who wants it:

http://www.amazon.com/ZyXEL-Wireless...SIN=B005WKIKA0

[rgleason]

Thankd RDr. You had this link before, but what I did not realize is that Android does not like AP.

[Markus451]

Originally Posted by LeaseOnLife

I have a couple of chart books and can access a decent scanner.

Does anybody know a free (possibly open source) tool to geo-reference these scans?

I know Fugawi has a "calibration" tool, but only stores the results as a Fugawi specific file.

SeaClear comes with MapCal, which I haven't tried that yet. It seems to export to "WCI" format

It would be great to find a tool to create charts from graphic files, compatible with opencpn.

IN CASE ANYONE STILL WANTS TO CONVERT PAPER CHARTS.. The current version of OpenCPN's helpfile has all that info, or more specifically it has the links to the OpenCPN website with all the info you need. Here's the link: Supplementary Software | Official OpenCPN Homepage

[Markus451]

Originally Posted by jackdale

Which chart were you using?

Most of mine are NAD 83 which is the equivalent to WGS 84, which is the GPS standard.

I've got all the RNC charts for BC and more than half are NAD27. The CHS charts now sold have the proper datum corrections, thus the datum listed in the chart legend isn't relevant, but mine don't. The issue is how can I enter the datum corrections so I don't have to lay out a grand for new charts. Unless someone is willing to share their charts.