MLAT stopped working after Winter 2023/2024 RPI Software update.

[vantage]

I upgraded my Raspberry PI per the AirNav instructions and after that MLAT stopped working. It used to work all the time. If anyone has any suggestions, I would appreciate it. I captured all the output from the commands to help diagnose the problem but when I try to post it I get:


An Error Has Occurred!
CleanTalk: *** Forbidden. [my email adress]: Mail domain for disposable emails. Contains contacts. Message seems to be spam. ***

The commands I ran but system will not let me post the output from:


uname -a   

lsb_release -a

apt-cache policy rbfeeder

apt-cache policy mlat-client

apt-cache policy python3   

sudo systemctl status rbfeeder


cat /etc/rbfeeder.ini

[abcd567]

@vantage

Please take screenshots and post as images. Please see screenshots attached below

[vantage]

[abcd567]

Everything seems good.
Cannot understand why mlat is not working.

[vantage]

Is there an explicit MLAT process or is it  part of another one? See screen shot what's running.

[abcd567]

Please see screenshot of "top" on my Pi.
The mlat-client is shown used by:

Left-most column:
- adsbexchange
- adsbfi
- adsblol
- rbfeeder

Corresponding Right-most column
- mlat-client
- mlat-client
- mlat-client
- mlat-client

[abcd567]

Better reinstall mlat-client

Code Select Expand


sudo apt install --reinstall mlat-client 

sudo reboot

sudo systemctl status rbfeeder 

top



[Runway 31]

abcd 

As he is using Buster should he not be on python3.7 for MLAT as i note python 3.5 in the ini file under MLAT

Alan

[abcd567]

Hi Alan
In the ini file, mlat_cmd line is commented out ( a # at it's start, due to which line color is blue). Therefore this line is ignored by rbfeeder and is ineffective. The rbfeeder itself finds & uses the appropriate python version available.

For example on my Bookworm, the python version available is 3.11 and although ini file shows python version 3.9, since this line is commented-out, the rbfeeder selects and uses available version 3.11. Please see screenshot attached.

[Runway 31]

Thanks for the info abcd

Alan

[vantage]

Better reinstall mlat-client

Code Select Expand


sudo apt install --reinstall mlat-client 

sudo reboot

sudo systemctl status rbfeeder 

top



Did the above and there seems to be a problem starting up mlat_client:
Jan 14 19:16:33 raspberrypi rbfeeder[466]:     open(pidfile, 'w').write(pid)
Jan 14 19:16:33 raspberrypi rbfeeder[466]: PermissionError: [Errno 13] Permission denied: '/run/mlat-client.pid'
Jan 14 19:17:03 raspberrypi rbfeeder[466]: Traceback (most recent call last):
Jan 14 19:17:03 raspberrypi rbfeeder[466]:   File "/usr/bin/mlat-client", line 108, in <module>
Jan 14 19:17:03 raspberrypi rbfeeder[466]:     open(pidfile, 'w').write(pid)
Jan 14 19:17:03 raspberrypi rbfeeder[466]: PermissionError: [Errno 13] Permission denied: '/run/mlat-client.pid'

[abcd567]

It seems mlat-client supplied from RB24 repository is broken.

First purge it

Code Select Expand


sudo apt purge mlat-client




Next build and install mlat-client from source-code as per method given in following thread. Please note that although the method says for Bookworm, but it is equally good when used on Bullseye and Buster.
   
Install rbfeeder and mlat-client on Raspberry Pi OS BOOKWORM

[vantage]

I did the purge and followed the instructions in the posted thread. This led to more problems. See attached file.


After that I tried something else  which also failed:

sudo apt purge mlat-client
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package 'mlat-client' is not installed, so not removed
0 upgraded, 0 newly installed, 0 to remove and 421 not upgraded.
pi@raspberrypi:~ $ sudo apt-get install mlat-client -y
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
mlat-client : Depends: python3 (>= 3.9~) but 3.7.3-1 is to be installed
               Depends: python3.9:any but it is not installable
E: Unable to correct problems, you have held broken packages.

[abcd567]

I did the purge and followed the instructions in the posted thread. This led to more problems. See attached file.


After that I tried something else  which also failed:


pi@raspberrypi:~ $ sudo apt-get install mlat-client -y
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
mlat-client : Depends: python3 (>= 3.9~) but 3.7.3-1 is to be installed
               Depends: python3.9:any but it is not installable
E: Unable to correct problems, you have held broken packages.

Using "sudo apt-get install mlat-client" wont work on Bookworm due to python version difference. The mlat-client supplied by Radarbox24 repository through "sudo apt-get install mlat-client" requires python 3.9, while Bookworm has python 3.11.

To solve this problem, build & install mlat-client on your Pi/Bookworm by method given in following thread:

Install rbfeeder and mlat-client on Raspberry Pi OS BOOKWORM



For your quick reference, I will repeat the method below:

Code Select Expand



sudo apt install -y git debhelper dh-python python3-dev python3-setuptools

git clone https://github.com/mutability/mlat-client

cd mlat-client   

sudo dpkg-buildpackage -b --no-sign   

cd ../

sudo dpkg -i mlat-client_0.2.13_*.deb

sudo apt-mark hold mlat-client 



[vantage]

Thanks for all your help. MLAT is now working. Within five minutes my station was synched to 12 others.