Beta Test / Technical

[rolker]

Hello all,

I'm a computer scientist working at the University of New Hampshire's Center for Coastal and Ocean Mapping. I recently got involved with NOAA's effort to send real time data via AIS binary messages and was looking for a way to display such messages on my Linux workstation.

Now, I'm not aware of any product, commercial or open, (Other than the specialty Whale Alert app for iPads/iPhones) that can display the messages I'm working with (IMO Circ 289) so I started adding support for them in OpenCPN.

I submitted a patch to the tracker under issue #382 where I implemented support for the messages currently being broadcast from Cape Cod, Massachusetts.
FS#382 : IMO Circ 289 AIS Binary Messages and TCP/IP support

As more message types get added for real time tide and currents, I would love to add support for those as well. So, is this the best place to discuss development?

Oh, and the above patch also contains a fix for a potential buffer overrun in the GetStr method that did cause the application to crash from an AIS message unrelated to what I was working on that was received from a live feed. (Moral of the story, don't expect all AIS messages to be well-formed!)

So, what kind of release schedule is used? I noticed a thread for a recent beta, how can I have my patch added if it's not too late to do so for next release? Otherwise, when roughly could I expect the following release?

Anyway, I hope I can make useful contributions to this great product and would welcome any feedback on the above patch, or any idea to make electronic charts more useful.

Roland

[bdbcat]

Roland...

Good timing. I'll take a look at your patch, and potentially get it into the next Beta release due this week.

Stay tuned
Dave

[P_Dub]

The use of this is already done for the pilots in the St-Lawrence and Seaway and it is very much appreciated. Such a system require an interface easy to use for the common seaman and should not be complicated to use. For instance in the Seaway it give the wind force and direction and also ships up or down and the availablity of the lock involve.
Bye
P_Dub

[rolker]

Originally Posted by bdbcat

Roland...

Good timing. I'll take a look at your patch, and potentially get it into the next Beta release due this week.

Stay tuned
Dave

Thanks Dave,

The patch is more of a proof of concept for the moment, I still need to make the notices disappear once they expired, which I should have done shortly.

Other issues where I could use more input from the community is how to display the details of the notice. I'm still new to the code base, but I'll look into the object query code to see if it makes sense to incorporate it in there.

Also, I decided to closely follow how the existing AIS code works, despite thinking that binary messages should probably be separated from AIS targets. I did this to keep my first patch smaller and minimize changes to the existing code base, but I could see a separate .cpp file in the future for handling binary messages as this code could grow quite a bit as more messages are added.

Now, before I add support for more message type, I'll take a look at how the existing tides and currents code work and see how well AIS data could blend into the existing capabilities.

Originally Posted by P_Dub

The use of this is already done for the pilots in the St-Lawrence and Seaway and it is very much appreciated. Such a system require an interface easy to use for the common seaman and should not be complicated to use. For instance in the Seaway it give the wind force and direction and also ships up or down and the availablity of the lock involve.
Bye
P_Dub

Yes, you're right, the St-Lawrence Seaways folks are pioneers in using AIS binary messages, so it would make sense to support those messages as well. I haven't seen how the St-Lawrence data is conveyed to the mariner. Is it only using custom systems the pilots bring on board, or do existing charting software support them?

The primary reason I started with the area notices as described in IMO Circ. 289 is so I would have somewhere other than an iPad where I could see the results of the Right Whale notices currently being sent out. Of course, I would like to see all existing (non-encrypted) binary messages supported, so I hope I can help develop the right infrastructure withing opencpn to support the decoding of such messages, and help provide a way to convey the necessary info to the mariner in a way that simplifies the display rather than making it more cluttered or complicated.

[P_Dub]

It is done via the AIS message received via the pilot plug connection on the chart program of NAVSIM that we have help and experiment. I am one of those that did it.
If you need to get the transmission code I could probably get it.
Bye
P_Dub

[petermoree]

Used the beta on board today.

Run under windows XP SP3
It crashed several times (a lot quicker when AIS button was set to ON)

see enclosed screenshots for details

[bdbcat]

Peter....

Beta 2.6.1624 has a known crash problem with AIS.

New Beta due soon.

Thanks
Dave

[svpresent]

I use a VIA computer, not the state of the art but fanless and economical on power. It's running XP3 SP3. OpenCPN has been on this computer for several versions now.
There is this problem of freezing after a few minutes with no apparent proof like a hourglass. I detect it when there is no more fluctuation in speed or course.
I need to move the map a little by mouse and then the hourglass appears en after say 20-30 seconds everything is back to normal.

Am I the only one with this problem?
Is there a way I can find out what actually happens when it freezes?
I can add that OpenCPN is the only program that shows this behaviour.

Many thanks in advance.
Cheers, Len.

[stedy]

Hi
($csymb) $code iq1302.2 is displayed as a question mark in 2.6.1623. It should be shown as a arrow and whit a angel following the farway(?).
Pleas se attached image. Have red marked the use of the 130.2 symbol.

[JesperWe]

Originally Posted by stedy

Hi
($csymb) $code iq1302.2 is displayed as a question mark in 2.6.1623. It should be shown as a arrow and whit a angel following the farway(?).
Pleas se attached image. Have red marked the use of the 130.2 symbol.

It has always been. The problem is that the chart database does not contain an ORIENT attribute for the symbol,so we don't know how to point it. And there is no point in drawing it pointing north always.
/j

[afmstm]

Hi,

I'm using build 1624 and want to report an "error" I have seen in OpenCPN for the last few versions (I first noticed it last summer). I'm using a GPS mouse via a serial port (with USB/RS232). I have not reproduced this on another GPS, so it is possible this is a problem with my GPS.

Occasionally (approx once per one or two hours) the GPS will send an invalid latitude or invalid longitude reading of zero for the value. This can be either Lat or Long or both. The GPS sentence is well formed (I've seen it in the log) but simply has zeros for the data.

OpenCPN will parse this and show the boat as being at the equator for just one second (with correspondingly high SOG! :-).

Normally, this is of no consequence - however, with an anchor watch set, this causes the alarm to sound for just one second, roughly every hour or two. This makes it hard to sleep!

I'd like to request/suggest that the code have some logic added to reject spurious data. A simple test for zero data that also has abnormally large SOG would probably suffice. Even though this may be an issue with my GPS mouse, it makes sense to have some logic that rejects obviously spurious data.

Less useful would be a change to the anchor watch logic to wait a few seconds before setting the alarm in case of a bad data point.

Thanks for an amazing product, that I use regularly.

Van

[manuprenlair]

Hello,

I saw that last beta version need Libgps20 unstead 19 to be compile.

I want to compile beta version for ubuntu 10.04.

The problem is that I didn't found any version of Libgps20 for 10.04...

So is there a way, or (I am a little confuse), like I saw in a post, it's finaly possible to compile with version Libgps19 ?

Best Regards

Emmanuel

[nohal]

Emmanuel...
Yes, it's possible to compile against libgps19 and nobody reported problems with it - the problems come when a package built against libgps19 is used on a system with libgps20 and vice versa as far as I can tell.

Pavel

[gpshephe]

Originally Posted by nohal

Emmanuel...
Yes, it's possible to compile against libgps19 and nobody reported problems with it - the problems come when a package built against libgps19 is used on a system with libgps20 and vice versa as far as I can tell.

Pavel

Pavel, I'm using the new version and am getting BSOD. It's happened to me twice. No special use, no active routes, I have GPS on com4, and a grib file active this time. Not sure last time. Just in it looking around. Not out sailing. sittin in a slip. I use W7 HP SP1 on a Samsung R540 laptop.

[manuprenlair]

Pavel,

Sorry for my misunderstanding.
It came from developer manual from OpenCPN.org
in Linux compile you could read:

"Important Notice, valid from beta 2.6.1718!

Developers note: libgps API changed significantly between libgps19 and ..20. We require the libgps20 API and include files to build OpenCPN, and a "version skew" warning will be produced if they are not found. The libgps interface will not function correctly if OpenCPN is built with libgps19 include files."

Regards

Emmanuel