rb feeder on RPI4 B does not work

[abcd567]

MLAT
Can you please post the content of file /etc/rbfeeder.ini? I am suspecting something wrong with setting under [mlat] in this file.

RTL-SDR V4 Dongle
(1) RTL-SDR V4, if genuine, is better than DVB-T.

(2) RTL-SDR V4 can feed 5V DC on antenna coax. It has a builtin software operated switch which can turn on/off the 5V DC to coax. This is useful if you have installed a LNA (RF amplifier) near antenna which can get 5V dc power on antenna coax. Do NOT turn on the dc swich of RTL-SDR V4 if you are not using LNA and your antenna has internal dc short.

(3) Many sellers on Aliexpress sell duplicate copy of the RTL-SDR V4, and not the genuine one.

RTL-SDR STORE:
https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/

RTL-SDR USER GUIDE
https://www.rtl-sdr.com/v4/

[CB17]

Here is a screenshot of it:

[CB17]

The RTL stick is exactly like in the photo, i sent. Unfortunately I can't say whether it's original or not. He is very sensitive on the PC (SDRAngel). But it doesn't work on the Raspi. Definitely a driver problem.

[abcd567]

(1) MLAT
In rbfeeder.ini, the setting under [mlat] is OK.

What is output of following command?

Code: [Select]

apt-cache policy mlat-client 


(2) RTL-SDR V4
On RPi, install drivers for rtlsdr and usb. Hopefully this will solve the issue.

Code: [Select]

sudo apt install librtlsdr-dev

sudo apt install libusb-1.0-0-dev 

sudo apt install rtl-sdr 

sudo reboot 


[CB17]

Hello,
this is what it looks like:

[abcd567]

The screenshot of output of command "apt-cache policy mlat-client" shows that although version (Candidate: 1:0.2.13+deb11) which is available from apt.rb24.com, you have installed latest version (Installed: 0.2.13) which you built yoursel from source-code by method posted by me above.
So far so good.

[SOLVED]
As next step, reviewed again screenshot of your file /etc/rbfeeder.ini, and found the root cause of mlat not working. Your ini file is missing following 3 lines under [client]

lat=xx.xxxx
lon=yy.yyyy
alt=zzz
(Replace xx.xxx by your actual latitude, yy.yyyy by your actual longitude, and zzz by you elevation above sea level in meter)

After making above changes:
(1) Save file rbfeeder.ini
(2) REBOOT Pi


Please see attached screenshot of my file rbfeeder.ini for guidance.

[CB17]

Fantastic!!! I can't believe it but it actually works. You are incredible, honestly.
I have no words to thank you for your effort.

The thing with the RTL V4 stick didn't work. It is original (as I saw it on the RTL internet site), but there is always an error message. Regardless, I don't want to burden you with this too.

[abcd567]

usb _claim_interface error -6
Failed to open rtlsdr device #0


The above error is given because the RTL-SDR V4 is being used by dump1090 (fa or rb or readsb). It is therefore not available for "rtl_test".

Before running command "rtl_test -t" you have to stop dump1090

sudo systemctl stop dump1090-fa piaware rbfeeder   

rtl_test -t

[CB17]

Ah alright then. But in normal operation it doesn't show any aircraft at all. Zero. I mean if I connect it instead of the DVB-T stick. It definitely works on the PC. And the sensitivity there is much higher than with a “normal” stick.
I planned to use it for the Raspberry 3B+. I also followed a bunch of instructions on YT, but didn't want to run. I saw that everyone always did this “rtl_test” after installing the RTL stick and it then showed something completely different. I always get this strange USB error.
Luckily I still had an Astrometa DVB-T2 stick in the drawer and thought, what the heck, I'll give it a try. It runs...but not optimally. Presumably the RTL Stick (if it were running) would produce much better results than the Astrometa. Well...you can't have everything.
By the way, the Raspberry 4 is now running fine. I am very pleased. I connected the Airnav radar box stick (green stick) to it and the COL1090/5-SU collinear antenna from Vinnant on the balcony. Even though I only have a clear view to the west and I'm surrounded by hills, I'm very happy with it.
Best regards

[abcd567]

there are 4 usb ports in RPi 4. Try to plug the RTL-SDR V4 dongle in all these one by one and see if it works in any of the 4 usb ports.

If you are using a USB extender cable, remove it and plug the dongle directly into usb port.

Also try to lightly squeez with thump & finger, the dongles metallic part which goes into usb port of Pi. This will help in a good electrical contact between dongle & Pi.

Also there is a strong likelyhood that there is some app on your Pi 4 (such as dump1090-rb, readsb etc) which grabs the RTL-SDR V4. I would suggest that you write RaspberryPi OS 64-bit Bookworm on a SPARE microSD card. Do NOT install anything on it except "sudo apt install rtl-sdr". Then test the RTL-SDR V4 dongle by command "rtl_test -t"


EDIT:
I have just now checked your file rbfeeder.ini and found that under [client], network_mode is set to false. This means when rbfeeder is running, the dump1090-rb also runs, and that is what is grabbing the dongle and as result "rtl_test" fails.
Please see screenshot attached.

You have to first stop both rbfeeder AND dump1090-rb, then run the "rtl_test -t".

sudo systemctl stop rbfeeder 
sudo systemctl stop dump1090-rb 
sudo killall dump1090-rb 
sudo systemctl stop dump1090-fa 

rtl_test -t 

[CB17]

I'll try later. If that would still work, then I would be happy. Many thanks and best regards.

[CB17]

That looks completely different. I can't believe it... Thank God I came across this forum.
This is what it should look like. I think it was the same with the others on YT.
And what do I do now so that the stick shows the planes? At the moment everything is empty. I haven't rebooted yet. Not that the Raspi automatically loads the dump again and then blocks the stick again... right?

[CB17]

Sorry, I forgot the screenshot... :-)

[CB17]

I don't have to reinstall the system again...right? Now that I know the stick is working.
Is there now a way to run the rb feeder so that airplanes also appear?

[abcd567]

It seems the dump1090-rb is not able to efficiently use RTL-SDR V4.

Better do following two things:
(1) Install dump1090-fa from Flightaware. Most users of dump1090-fa report good performance of RTL-SDR V4.

(2) To prevent dump1090-rb grabbing the RTL-SDR V4, STOP dump1090-rb permanently by changing setting in /etc/rbfeeder.ini

Under [client]

Change:
network_mode=false

To:
network_mode=true

After above modification, save the file rbfeeder.ini, then REBOOT the Pi.

sudo reboot

Reboot will restart dump1090-fa and rbfeeder, but without starting dump1090-rb. Thus dump1090-fa will be able to grab and use RTL-SDR V4. 

Most likely using dump1090-fa instead of dump1090-rb will solve your problem.