LMS-520C & map orientation problem

[ScottL]

I have a 520C in the bow and a 27C on the console networked together. The GPS puck is mounted towards the transom. I've noticed that when I'm using the bow mount trolling motor,watching the 520 and going at speeds less than .5 MPH that the map orientation is very slow to react when I change my direction of travel. This past weekend was fairly windy and I found it very frustrating trying to follow the contour lines on the Lakemaster chip because the GPS background map didn't orientate as fast as I think it should. When I'm trolling at speeds of 1.5 + it seems to be fine. I have played with the orientation function and tried North up, Course up, and Track Up. I prefer the Track up mode. In GPS setup I disabled the track smoothing function. I was wondering if it has to do with the GPS puck being mounted aft or if is more than what the co-processor in the 520 is capable of processing(split screen map and sonar with Lakemaster's hi-def 1ft contour map) which is awesome by the way.

[hondo]

It's slow to update because if you're not moving very fast (ie. you said .5 mph) so there's not as much to update as when you're moving faster (ie. 1.5 mph).

For situations like you described, I run my plotter in North Up (so the map and countour lines don't bounce around so much) and I put my trail update rate as high as it will go --- that seems to be work for the best for me.

[ScottL]

What bothers me the most is that I can turn the boat completely around and be going the opposite direction for a minute or more and the map still will not have changed it's orientation.

[GBS]

Try it without the chip for a bit. I think you'll find it is the same. Sounds like an issue with antenna update time, positioning error, and /or number of satellites seen. You're moving so slow, the updates to the unit are inside the current margin of error for the GPS, hence no map redraws happen until the software has detected you have moved enough. If you see that you don't have WAAS or many satellites locked, you can play with antenna positioning to try to improve it.

[Backwater Eddy]

Relocating the GPS module may improve your satellite reception?

Or, if the module appears to be weak or just not doing the job, consider upgrading to the new 4000 series gps module, far faster updating..5 times per second...should do the trick.