Garmin GPS 19X Programming

[sy_gilana]

I hope someone has done this so that I don't need to re-invent the wheel.

My GPS 19X is too accurate, it is confusing my autopilot in that any roll or wave action is interpreted as a change in COG and SOG.

I want to filter the NMEA (4800) stream to an average over a few seconds.

The $PGRMC sentence contains in position 11 a value of "Velocity filter, 0 = No filter, 1 = Automatic filter, 2 to 255 = Filter time constant (e.g. 10 = 10 second"

Has anyone tried this? What is a good filter time? What interface did you use?

[smac999]

I doubt your pilot is using either of those.

probably your heading sensor that can't handle the waves.

which pilot / heading sensor. what is actual issue?


assuming the GPS feeds a plotter. and then a plotter feeds the pilot. you can probably filter in the plotter.

[zboss]

You can change the sensitivity of the autopilot in Dealer mode. I forget the key combo on the autopilot but you need to be on the system information page first before keying in. I think you just hold down the center key for 5 seconds or maybe it’s a combo of keys. After that you will see “dealer mode” appear on the screen. When you go back a few pages you will see additional options available for tuning the autopilot.

I’d take the time to go through the setup wizard first. You will need lots of flat open space to do it right.

Then take a picture of the gain settings and so forth with your iPhone and then learn to tweak it.

If I recall correctly, the latest update includes some additional settings that you can adjust on the fly without going into dealer mode.

[sy_gilana]

Thanks guys it has nothing to do with the pilot. I have been setting up AP's for nearly 20 years. I know its the GPS, When I use OpenCPN to feed the AP all is good, but I don't want to run like that. The GPS can send position and speed info at 10 Hz. I have slowed it to 1Hz, but its still too fast.
Examining the NMEA stream, I can see that the speed and direction traveled is too sensitive, it is accurate, it is reporting the movements of the sensor correctly.

The autopilot settings do help a little bit, but I would like to filter, ie Averge the feed from GPS to pilot.

Anybody done this on the 19X OEM GPS?