Hello everybody!

I really can't find a solution for this problem.
I hope someone is able to help me?
so, i'm running Puredata on a Raspberry Pi and I

I inserted a line in the autostart file in order to open a Puredata patch at startup and the patch get successfully loaded.

The Puredata patch uses NETRECEIVE since receives instructions from Python.

Everytime the patch opens, I receive the error: "bind: address already in use (98)"
of course i tried to change address but at start up i receive the same message

if a type ''top'' command on the terminal, shows me 2 processes of Puredata running and i believe that this is the cause of the problem. (one process starts on the back and takes the occupy the port

I'm aware that the topic is not strictly Puredata but many of you have shown deep skills in such different environments, therefore you might be able to help!
thanks in advance

Is it possible that you have multiple copies of Pure Data on the Pi?
Perhaps you installed it and then moved it but did not delete the previous installation?

If the "address" it refers to is the port number, than you could keep trying with different port numbers, it could be that you are using a port number already in use by your system.
I realize that I am not sure how to view this on linux but for sure there will be a way if you research it...
however, if the problem is that for whatever reason you are opening 2 instances of Pd that have the same port number saved or loadbanged into the patch than maybe a test could be to delete the port number from the patch and make it so that you enter this manually after the patch opens
then try it and if it works but still shows two instances of pd running then the problem is that you have multiple Pds being opened at the same time somehow.

In that case, perhaps deleting any Pure Data installations on the Pi and re-installing would solve it.

@nhouse If this is happening from a cold boot then the autostart script must be opening Pd twice.
As @Coalman says maybe with multiple copies the script would open both...... but I would suspect an error in the script is more likely.
Post your script and someone clever with Linux will tell you straight away.......
David.

@Coalman if for example, I have set Netreceive 3000 at startup, I receive the error of ''address already in use''. In this case i change it with 5000, close the patch and open again and i don't receive the same error anymore. BUt at the next startup the error comes back. This (plus the 2 puredata processes that i see after i type the ''top'' command) leads me to believe that the patch gets opened twice.
The operating system is new but indeed i will try to unistall and install puredata again. That could be true.
@whale-av the line that i wrote in autoscript is just:
pd path/to/file.pd

i also tried to open it from within a script with the following

import time
import os
time.sleep(0.2)
p = os.popen('pd /home/pi/Desktop/Main_Patch_Pd/main_patch.pd')
time.sleep(0.2)

@nhouse I am no Linux expert..... but I wonder if just

path/to/file.pd

would work as then the file might open Pd.
It could be that the previous "pd" opens pd (seems likely) and then the path to file opens another instance?
David.

@nhouse Does the patch use [pd~]? If so it runs a second instance of pd as a child and top does not do the best job of showing it as a child process, htop is a good replacement for top, press t and you get a tree view, plus it uses colorized output to make things easier to read along with a pile of other handy features like process management. If that is not the case, what is this autostart script? Do you know what program it is part of? Failing that, what is the full path to script and what flavor of linux are you running?

the autoscript file is accessible here

sudo nano /etc/xdg/lxsession/LXDE-pi/autostart

at the end i discovered that GPIO 20 and 21 of the RPi were fried. i replaced the Pi and now i don't get the double Puredata instance anymore. this will keep been a mistery