OCPN vs Navman autopilot

[Jim Cate]

Once again I've been trying to get OCPN to successfully drive my NavMan 3100 autopilot with no success. The symptoms are:

All the appropriate nav data are accessible to the a/p, and can be displayed on it.

When placed into "GPS" mode, the a/p will happily follow the course to the next w/p. When it reaches that w/p, it displays "route ends", sounds an alarm and reverts to compass steering.

At this point, the a/p still knows that there is another w/p, the bearing and distance to it and will display that data on demand. I can dismiss the compass mode and manually return to GPS mode and restart it, and the sequence repeats.

In contrast, before switching to OCPN I used a Northstar GPS and it worked properly when connected to the a/p, following from one w/p to the next.

I have tried outputting various combinations of NEMA sentences from OCPN to the a/p, including duplicating those employed by the Northstar. No differences in this faulty behavior have been noted. I have tried both checking and not checking the "advance waypoint on arrival only" box in the setup, again with no change.

At this point I'm stumped, and would welcome any advice.

Jim

[nohal]

Originally Posted by Jim Cate

At this point I'm stumped, and would welcome any advice.

And so are we. Are you able to record the NMEA datastream when your old GPS drives the autopilot and a waypoint is reached?

Pavel

[Hakan]

Jim..
For me it's surprising you have got your AP to automatically change from one WP to next while following a route.
My experience with, so far, all WPs is that when I reach next WP I have to "acknowledge" every new leg with a press on "Nav Mode", or similar, button on the WP, after the beep. That's how they are set up and I believe it is for security reasons. You've to be aware of and confirm every course change.
If your AP is set up in another way it's rather unusual.

As Nohal wrote the GPS data stream that forces your AP to this uncommon behavior would be rather interesting.


Håkan

[Jim Cate]

Nohal and Hakan, thanks for the replies. I appreciate your insights.

Sadly, the northstar has been out of service for some years now, and tracking down its data stream isn't possible. I did look back in the records and found that it was outputting (according to the manual) the 0183 sentences APB, BOD, VTG and XTE. So, one of the permutations I tried was setting OPCN to output only those sentences. No improvement in function noted.

I'm unsure as to what the "advance... only on arrival" function means. Sounds as if it should have something to do with this issue, but does not seem to have any effect. Can you help me understand this, please?

If a single button push was all that was required to advance to the next waypoint, I'd be fairly happy, but with this a/p it requires several, and in a non-intuitive sequence. Problem is that if there is very much delay the XTE can increase to the point that the a/p will not go into GPS mode without zeroing the XTE, requiring a trip below to the computer. There may be a way to get around this, but I've not discovered it yet. Unfortunately, since the demise of NavMan, there is no one to offer support from that end.

I seldom use the GPS steering mode, but under certain conditions it is very useful for following a route with lots of short legs and significant currents setting one off course, so I'd like to get it working.

Thanks for any further ideas you might have.

Jim

[seandepagnier]

you could try the autopilot route plugin. It has a lot more options, as well as output differently and you can configure a lot more options.


Otherwise... maybe time for new autopilot! pypilot can follow routes without any human interaction. It also has the best integration with opencpn for any autopilot with special plugin and watchdog support.

[Jim Cate]

you could try the autopilot route plugin.

Sean, I'm kinda dense, but I don't see this plugin listed. Where do I find it?

Jim

[Bill O]

Originally Posted by Jim Cate

Sean, I'm kinda dense, but I don't see this plugin listed. Where do I find it?

Jim

Jim,
I think Sean is pointing you to Route to Autopilot plugin

If you can't get your AP to work, maybe switch to Sean's Pypilot. We have done some preliminary tests on his new AP for below deck hydraulic steering units and its working well. We will be doing more extensive testing in the next couple of months while out, but so far, its 2 thumbs up!!


Bill O.

[Jim Cate]

Originally Posted by Bill O

Jim,
I think Sean is pointing you to Route to Autopilot plugin

If you can't get your AP to work, maybe switch to Sean's Pypilot. We have done some preliminary tests on his new AP for below deck hydraulic steering units and its working well. We will be doing more extensive testing in the next couple of months while out, but so far, its 2 thumbs up!!


Bill O.

Bill, thanks for that. I have now downloaded and installed Sean's plugin, but can not find it in the list of plugins in the settings tab. It is present as a .dll file in the OCPN file, but I'm too dense to understand how to proceed from here.

Sorry to be so slow, but could someone walk me through the process, please?

Jim

[hoolie]

I get the same. I think the problem is this plug-in is only compatible with OCPN version 4.99 which hasn't been released yet. If you're up for compiling the new version then you might get the pi to work but if, like me, you're not we are just going to have to wait. I think this version of O will be formally released as 5.0.

[Jim Cate]

Originally Posted by hoolie

I get the same. I think the problem is this plug-in is only compatible with OCPN version 4.99 which hasn't been released yet. If you're up for compiling the new version then you might get the pi to work but if, like me, you're not we are just going to have to wait. I think this version of O will be formally released as 5.0.

Ahh, so! Thanks for that... I'll sleep better tonight not wondering why I'm so damn ignorant.

This whole question has been frustrating for me, and the more I can learn about the workings of O and my aging a/p the better.

Jim

[Bill O]

Jim,
We switched all our nav and AP computers to Rpi. A bit of a learning curve for me (an older not a super electronics guy), but the whole system is slick. Would highly recommend it if you get a chance and you want to upgrade your system.
We originally compiled the O to our pi, but in the long run we went w/OPlotter to get Sean's embedded AP program and a better multiplexer. OP is easy to down load and still contains O.


Bill O.

[seandepagnier]

Originally Posted by Jim Cate

Bill, thanks for that. I have now downloaded and installed Sean's plugin, but can not find it in the list of plugins in the settings tab. It is present as a .dll file in the OCPN file, but I'm too dense to understand how to proceed from here.

Sorry to be so slow, but could someone walk me through the process, please?

Jim

This requires the latest opencpn... I had thought it was in 4.8.4 but I guess not, sorry.

I doubt it would solve your issue, but might be worth a try.

[rgleason]

OpenCPN has a number of Autopilot options, so it can become confusing to the new user.

The links below do not work properly, so here are a number of Autopilot related links with explanation. Feel free to clarify further:

OpenCPN: Advanced - Route to Autopilot explanation
This explains how OpenCPN itself handles waypoint arrival when Sending an Active Route to Autopilot

Pypilot Autopilot Plugin - To be used with Pypilot or Tinypilot RPI Autopilots. This has newer autopilot logic for following a route utilizing Pypilot RPI Autopilots.

Autopilot Route Plugin - Provide Configurable Autopilot Route following abilities for OpenCPN. The autopilot route plugin (beta) is a completely separate plugin to be used with any autopilot. It allows you to use different algorithms and closely tune them for route following logic. It has nothing specific to pypilot. This plugin allows the user to select different algorithms and closely tune them for route.

Autopilot Raymarine Plugin - Provide an OpenCPN Autopilot Control for Raymarine Autopilots. Autopilot can control a Raymarine autopilot by sending and receiving special NMEA messages to the course-computer.