@oid I had a similar opinion and similar worries.
Bluetooth pairing with a pairing password in Android sometimes ties the device to a single app, the data stream..... and even the connection state.... then not being available to any other.
No idea how that is dealt with in Linux..... so no comment except that the information will have to be found in Linux forums I think.
David.

@bobfred I see you still have portaudio selected rather than alsa or jack, before you opened audio settings... maybe that has an effect?
Could it be that only 2 channels are made available from Pd because "system" only has 2 output channels?
Is there a way to aggregate your 2 Bluetooth devices as a 4-chan device in a similar way to creating an aggregate device on a Mac or using Asio4All in windows.
I think that for a 4-chan stream to be accepted as an input you will need a 4-chan device as output because it will in fact be a single (probably interleaved) stream so that timing is preserved between the channels.
For that you might be able to specify the system output by changing ~/.asoundrc like this...... https://stackoverflow.com/questions/15592187/5-1-channels-with-portaudio
....but that is a wild guess and I think you should google "Linux aggregate device".
It seems that Jack has an "aggregate device editor" and pipewire probably has something similar....
David.

@mechanatura I cannot test for the rpi.
I have never seen arguments included in [pix_video]... only messages sent into it. Maybe that is a Linux peculiarity. Maybe this will work........ pix_video-help.pd
It has a few tools that might help to see what is /is not working.

I had the same problem with some versions of Gem on my Mac years ago and this
https://github.com/extendedview/extended_view_toolkit
got the camera working. I never worked out why it worked where nothing else would.
It is a very interesting library anyway, so worth having for video.
It is old..... so might rely on some other libraries from the days of Pd extended, but the abstractions are mostly vanilla (+ Gem).
David.

@mechanatura What do the messages to the Pd console say as Gem is loaded?
Do they mention (usually at the end) that there are backends missing or that are required?

Have a look there for error messages as [pix_video] is loaded.
If there is just one camera then it probably is 0 ... but I have had it found as 1,
10 is unlikely.

I don't know much about the RPI.
Are you opening [pix_video-help] when trying to use the camera?
David

@blindingSlow I might be adding nothing new to the post from @oid.
In windows Pd vanilla this works..... curve_cords-plugin.tcl ..... but is not very pretty even with wish86.exe.

and for objects vertically stacked as in your OP it really doesn't work at all....

However, I believe the code in the plugin was lifted directly from Pd-L2Ork. so relied on the Pd-L2Ork GUI.
The code in the plugin is pretty straightforward, and so it might be improved fairly easily for Vanilla?
It looks as though -smooth 1 -splinesteps 36 are not behaving in tcl....... https://www.tcl.tk/man/tcl8.4/TkCmd/canvas.htm#M139 .... but it seems tkinter (part of Python) would need to be installed? I am really unsure about that and I don't see why it should be necessary.
David.

@oleathlobhair When you set the input and output in the Pd Media Audio settings tab there is no longer just an apply and OK button, but also a "save all settings" which should store the setup to the registry.
If you click that button once you are set up and working properly.....do you still have the problem when you restart Pd?
David.

@oleathlobhair Are you using the computer soundcard, or an external one?
And keep an eye on https://forum.pdpatchrepo.info/topic/14966/audio-i-o-error in case a solution is posted there....
David.

@porres You are correct about rotation.
Just for info..... as you don't have extended..... hope it helps.....
David.
P.S ... and thank you for all your hard work..

@dvd01osclfo Using an [array] is probably not the best way to do it, but it does give you a graphical representation of the notes.
You will need to increase the height of the array window if you put notes over 1000.... it will still work but it will look strange with bars outside the window.
Try this..... huh-mod.zip

You get one extra index with a value of zero, but the message to [random] ensures that it is ignored.
That can be fixed of course..... but no more time right now......
David.

@blindingSlow Hello! and welcome to the forum.
The Pd GUI is built with a program called Wish.
Wish is a graphical shell for the Tk/Tcl programming language.

Inside your Pd installation folder there will be a folder "tcl" that contains all the tcl scripts that build the GUI and control its behaviour. They then tell the operating system how the windows should be drawn on the screen, so commands sent within the scripts will be different depending on which os you have.
I think pdtk_canvas.tcl does most of the work.
A reasonable explanation is included as a comment in the .tcl files.

There is an external.... [sys_gui] that can send commands to the tcl proc's.
You can change the background colour by sending the command... tk_setPalette background [tk_chooseColor] ..... as a message..... into [sys_gui]

And myname-plugin.tcl files can be made and placed in Pd search paths to modify the tcl as Pd starts.
E.G. cordarrows-plugin.tcl which will add arrows to cords when in edit mode.

You can permanently change the tcl...... as in PdNext.......
Here are some of my feeble attempts..... https://forum.pdpatchrepo.info/topic/9960/tcl-for-a-rainy-day
https://forum.pdpatchrepo.info/topic/9991/woof-a-new-window-menu-for-vanilla-tcl
New items can be added to the Pd menu drop down choices by modifying pd/tcl/pd_menus.tcl and pd/tcl/pd_menucommands.tcl

I am not a programmer either, but other people on the forum will be able to help you.
David.