OpenCPN RPi Serial Port Problem

[jh004]

I am setting up a Pi4 with OpenCPN 5.6.2 and Pypilot and using USB serial ports for NMEA 0183 data and GPS on separate ports of a Zero4U 4-port hub. The GPS is a Ublox dongle. NMEA data is from Seatalk through a Brookhouse multiplexer, powered on a different circuit to the Pi.


If I start the Pi, open OCPN then start the multiplexer all is good.


If I start both together, or close OCPN then reopen, I don't get any data or GPS. However, if I open Route Manager and activate a route, data is then available. Data from both ports appears to be available in Minicom at all times.


Is this a quirk of the setup or a problem in settings or OpenCPN? John.

[mgrouch]

Originally Posted by jh004

I am setting up a Pi4 with OpenCPN 5.6.2 and Pypilot and using USB serial ports for NMEA 0183 data and GPS on separate ports of a Zero4U 4-port hub. The GPS is a Ublox dongle. NMEA data is from Seatalk through a Brookhouse multiplexer, powered on a different circuit to the Pi.


If I start the Pi, open OCPN then start the multiplexer all is good.


If I start both together, or close OCPN then reopen, I don't get any data or GPS. However, if I open Route Manager and activate a route, data is then available. Data from both ports appears to be available in Minicom at all times.


Is this a quirk of the setup or a problem in settings or OpenCPN? John.

You might have to set up udev rules for your devices to be named consistently independent from order they are plugged in and booted.

Have you tried Bareboat Necessities OS for pi4? You should have less of issues like that with it.

[jh004]

I think I may have stumbled across the source of the problem and, hopefully, a possible solution.


I had Pypilot running as a service on the rpi. Looking through the syslog for the source of another issue I saw that Pypilot was latching on to the same serial ports that OpenCPN was using. Depending on which one got there first determined which program had the data.


Pypilot uses localhost 127.0.0.1:20220 as its data port. Listing this as a data connection on OpenCPN in addition to the serial ports seems to overcome the data problem. On my system, the serial ports are also used to send data to the old Raymarine autopilot. I have not tested to see if this works yet.


John

[jh004]

So the feed to the old Raymarine autopilot didn't work as I suspected it may not. Back to square one. At least I have a cause, still working on a solution.



This is more a Pypilot problem. Any further results I will use that forum.


John