Originally Posted by redbopeep
You can check you're getting decent data from your device by using:
you're likely seein nothing until the serial speed is set correctly. So you need to know your baud rate for your AIS data coming in. Ours is 38400 but standard NMEA0183 is only 4800. So, you can set it use the stty command (think stty 38400 /dev/ttyusb0 ) and then when you do the cat command you should see sensible data you can read. Otherwise try stty with other baud rates until it's working.
Other problem can be permission related--do you have the correct permission set so you can see the port? As your user you need to ls-l to the port name you can see the group name for that port and you need to be a member of that group.
Once all is working, you can write a udev rule that will recognize the device when it's plugged in, set the baud rate, and give it a unique name that you can put into OpenCPN. And, there you go.
Thanks for the advice; this stuff is a bit beyond my Linux level, but I'm glad to learn it. I tried the cat command and got nothing, i.e. it just hung till I broke it. I then set my user name to the root group (found that with the ls -l command), and when I do a cat on either of my devices, there is a pause then it returns to command prompt, no output. Using the stty command without a number shows the current baud rate, and my gps showed with 4800 and ais with 38400, and OpenCPN agrees with those numbers and is working with both units.