New rtlsdr Plugin

[piluso]

I am tired of screwing around with things that don't work

I really understand you.
I think this is still in an early stage of development, and a lot of work must be done before be considered ready to use for any user, a good auto calibration routine is imperative.
How simple it would be if the dongle came with the ppm printed in it :-)

[rgleason]

That would be a very good idea!
If I got a good ppm value that is always repeatable i86.400 mhz auto calibrate with rtlsdr-scanner results -4.561 ppm always. Can I use that?

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[piluso]

If I got a good ppm value that is always repeatable i86.400 mhz auto calibrate with rtlsdr-scanner results -4.561 ppm always. Can I use that?

Sure! The ppm error is a constant for a given dongle. Try -5, good luck !

[Sailoog]

To easy calibration on Linux:

Install https://github.com/steve-m/kalibrate-rtl

and follow the steps: Navigatrix.net - A Voyager's Companion • View topic - How to calibrate RTL-SDR AIS properly

works 100%

[rgleason]

Using Sdr# most recent version with vhf antenna connected and 161the.975 mhz with ppm set to -5ppm I get 40 db difference. When ppm set to -6 or -4 the db goes down to 36 db. There is a good signal at 161.975 mhz with a decent base. No engine on.

Now according to Sean there is no "connection" required in Opencpn. I just have to put -5 into the rtlsdr_pi preferences "error correction" field. Selecting AIS "enable" button. Then Ok.

No Ais targets seem to show up. Am I missing something here?

[rgleason]

From MS visual studio command prompt
In the plugin/ftlsdr_pi/bin directory when I run
Rtl_fm -f 1619750000 -p -5 -s 48k (pipe vertical) aisdecoder -h 127.0.0.1 -p 10110 -a file -c mono -d -f /dev/stdin
Fp 75C99C08
Found one device
0: Realtek RTL 2838UHIDir Sn: 0000001
Using drvice 0 : Generic Rtl2838U oem
Found Rafael Micro R820T Tuner
Tuner gain set to automatic
Tuner error set to -5 ppm
Tuned to 162227000 hz
Oversampling input by 21x
Oversampling output by 1x
Buffer size 8.1 ms
Exact sample tate is 1008000.009613 hz
Sampling at 100800 S/s
Output at 48000 hz.

=========

When i try this command from the normal command prompt
The device is found as Generic RTL2832U oem

But it says usb open error -3
Please fix device permissions eg by installing udev rules file rtl-sdr.rules
Failed to open rtlsdr device #0

Please read above carefully. The commad runs and completes using the MS Visual Studio command prompt from the bin directory, but not using the normal run cmd prompt from the bin directory.

Is this a problem?

How do I get this working in windows 8.1 under opencpn v4.1.602?

[rgleason]

Is it possible that the dam Norton firewall is trying control usb signal devices? Perhaps Norton Firewall should be turned off.

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[petter5]

Originally Posted by rgleason

Is it possible that the dam Norton firewall is trying control usb signal devices? Perhaps Norton Firewall should be turned off.

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Norton or McAfee - should be uninstalled

https://www.youtube.com/watch?v=bKgf5PaBzyg

[rgleason]

Would dearly love to uninstall, but instead will turn it off. Quite frankly I don't think it is causing the problem but will check.

I believe the dongle is working properly and we are getting AIS signals and we are using the correct PPM (-5) for this dongle.

However the right connecttions or something are not in place to see AIS in OpenCPN.

Perhaps I should try running AISDecoder to see if this is right.

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[rgleason]

Having determined -5 ppm and checked thid in HDSR and rtlsdr-Scanner, I tried -5 ppm in Opencpn rtlsdr_pi from Piliso, with Norton firewal and antivirus off, connected to vhf antenna, Right clicking on Opencpn start ion and selecting Run as Admin even though I have Admin privleges as a user. There were no AIS signals with rtlsdr_pi open
1. With no special connections for Ais - as sean says it is not needed the plugin does the connection.
2. Using UDP 0.0.0.0. and port 10110
3. Using UDP 127.0.0.1
and there still was no ais signal.

So then I tried to calibrate with the plugin starting with -5. That ended with -98 so it failed.

The dongle is not working under Opencpn, or it is working but the nmea stream is not geting to opencpn.

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[rgleason]

This morning I tried the same routine with opencpn 4.0 and its rtlsdr_pi plugin. No AIS signal and cabilbrating results in -98.

Also aisdecoder is not recieving AIS signals when run as administrator in stanalone mode, But I do see the nmea GPS signals.

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[LeoA]

Can you tune to the NOAA weather channel that broadcasts in your area and hear it through your speakers with SDR#? If you can, put up a screenshot of SDR# tuned to the NOAA weather station

[rgleason]

Ok LeoA. I hope this is what you would like.
I put the -5 ppm and this is what I get in SDRsharp. I also have another pic from another program HDSR in the same range using the same -5 ppm.

I can hear static sound but not the broadcast. What do you want me to hear.

[LeoA]

Right now, your radio stick is not receiving a signal. Make sure you are tuning to the NOAA weather frequency for your area, 162,475,000 for Boston, I think. Under the radio tab, you need to check the NFM (narrow fm) checkbox for vhf radio and ais reception. You also need to increase the number in the bandwidth box to 12500. In the rtl-sdr controller box, set the sample rate to 2.4 MSPS, offset tuning unchecked, rtl agc checked, tuner agc unchecked. Slide the rf gain control to around 40 and leave the ppm at 0 for now. When the sdr dongle is tuned to a signal that you can hear it should look similar to my screenshot. My reception is not real strong as I am not at my boat and am using the small antenna that came with the dongle.

[rgleason]

We are in RI right now but using the Boston 162.475 mhz signal we get -38db at 162.475 mhz with the settings and i structions you provided. I will attach the photo separately. I can hear a hissing sound when I turn up the audible control in SDRsharp.

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