SDR VHF processes openplotter-rtl_ais inactive dead

[shinken]

My setup is a RPi 4 with a fresh install of the Stable Starting image of OpenPlotter. I have deactivated the autostart of OpenCPN 5.6.2 and installed instead OpenCPN 5.8.0 FP. Everything works. On this barebones system (I have only added some charts) I have plugged in a USB GP dongle which works great via GPSD. Then plugged in a USB SDR VHF adapter which is recognized. I went through the calibration procesure as pr the SDR VHF Tool of OpenPlotter. I get a PPM of -7. All the tool seem to work except when I get to Processes. Then I get this error: "openplotter-rtl_ais inactive dead." I tried to Start the process, Stop and Start again, Restart. It seems to try to do something but in the end the process remains inactive. I also tried reboot with no luck.

Any suggestions?

[shinken]

One thing ocurred to me...before I switched to OpenCPN 5.8.0 I had installed SDR VHF process under OpenCPN 5.6.2. Could it be that something is still running from that process and blocking access to the SDR VHF USB stick? If so, how can I check it? How can I stop that process?

[holgerw]

you last idea is an possible tip:
"htop" will show you the running processes. from here kill the process.
then try to start the process from the openplotter plug.

look for sdr or rtl.
the services start from an script in /etc/services/ ?

holger

[shinken]

Thank you Holger. I run htop and found no SDR VHF processes running. I looked under OpenCPN 5.8.0 Connections and all I see is the USB GPS. Under Serial 3.2.0 there's only the USB GPS listed. Using lsusb I can see that both the USB GPS and the USB RTL_SDR are plugged in.
So I tried to re-calibrate the SDR VHF as I do have access to those options. The PPM is now -127 from the original -7. Wierd. Is this normal? Anyhow after doing that the Connections under SDR VHF show that the AIS entry is ACTIVE! Hooray! But not for long I can't see any AIS targets on the OpenCPN screen. Am I missing a step? I still see no new connections under OpenCPN or Serial despite that the AIS process is running.

Totally confused!

[Sailoog]

You will not see any serial connection in opencpn or openplotter-serial because the SDR device is not a serial device. The process that now you can see active is in charge of sending data to the signal k server and the signal k server will send data to opencpn, is the connection to the signal k server missing in opencpn?

-7 and -127 is a big difference, try to get your correct ppm using the calibration process and take your time. You need a VHF antenna, the small antennas supplied with some SDR devices will not work.

I just realized that docs for OP3 are not added for this, you can follow the docs for OP2: https://openplotter.readthedocs.io/en/2....f/ais.html

[shinken]

Thank you.

I am now able to see the connection under the SDR VHF window and it is active. There's also a connection from Signal K to OpenCPN on port 3000.
I will rerun the calibration. This particular USB dongle is said to have a TCKO of 1 PPM. I think I'll let the calibration for the initial PPM run for several hours and see what I get.
I am using the boat's VHF antenna. Is there a way under SignalK to see if I am receiving data from the dongle? I apologize for these questions I am just getting started with this.

[Sailoog]

"This particular USB dongle is said to have a TCKO of 1 PPM."

Then that is your PPM, no calibration needed.

Go to http://openplotter.local:3000/admin/#/databrowser the AIS targets will appear in the upper left field where you can read "self"

[shinken]

Thanks so much. It's working!