[Elecraft] COM port problems

[Dave B]

FYI...

Windows users, can use these utilities to find out what is/was connected 
to their PC's by USB etc...

USBview:  A Microsoft (was System Internals who MS bought) tool.
The easiest way to find it is here:- https://ftdichip.com/utilities/  
"Microsoft USBView - USB Connection Viewer"
There is a link to download a zipfile that contains it:- 
https://ftdichip.com/wp-content/uploads/2020/07/usbview.zip
That contains a single stand-alone exe file that is the utility. Put it 
in a folder of it's own, and create a shortcut to it for your desktop.

(Also a link to a Linux version, that does work, but needs compiling 
from source, and running using sudo as it needs elevated rights to read 
the running configuration files to get the information to display.)


Another similar tool is USBDview 
https://www.nirsoft.net/utils/usb_devices_view.html
That shows a much more detailed list of what Windows knows about, that 
is, any USB device that was ever connected since windows was initially 
installed, regardless of if it was ever used!

You can also delete instances of old / defunct devices easily with this 
very useful tool.
(Some AV tools say it's suspect or malicious.  Use VirusTotal.com to 
verify if it (or anything else) is bad, on a file by file, or webpage 
basis. )


Note that if for whatever reason Windows (or Linux) re-enumerates 
things, the linkage between a physical device and it's COM port number 
can (and often does!) change.  Seemingly at the will of some minor deity 
somewhere...   That of course, will break any software that expects some 
specific device to be at a specific COM port.

Windows has the means to "Fix" that.  (Known to work up to Win10, that I 
have personally tested it on.)
Find those details here:- 
https://sourceforge.net/p/fldigi/wiki/windows_com_howto/
I wrote much of that after hours of "fun" some years ago...   As above, 
it works well with Win-10.


For Linux users, look up and explore the world of "udev rules". But...
They are only really easy to setup, if a USB device has a unique 
"something" in it's USB descriptor, that the OS uses to identify it.  
Such as a Serial Number.   FTDI devices have unique sn's, but Prolific, 
SiLabs and others sadly do not.  So, it gets funky if you have several 
of the same type of device that all "look the same" to the OS.

(Newer genuine FTDI devices also have the ability to have that serial 
number (and some other settings) re-programmed!   Fakes seem to take the 
reprogramming, but the new data does not "stick".  Don't ask how I found 
that out!)

However, you can use the "connection path" between the OS and the 
Device, as a deciding factor, but then you are forced into hooking 
everything up "EXACTLY" the same each time.  (Hub's and all...) But it 
does work.

Using them, you create "symbolic links" to the actual port used, so for 
example my VHF radio appears as /dev/ttyFT736  Regardless of which hole 
I connect it's associated FTDI serial adapter to on the PC (or via any 
hubs!)  Or what /dev/ttyUSB* the OS re-assigns it to if things are 
re-enumerated for whatever reason.)

For example, this is the rule for my ancient FT-736

#FT-736r
SUBSYSTEM=="tty", ATTRS{serial}=="A50285BI", SYMLINK+="ttyFT736"

Flrig and most other software both accept symlinks and work well.

(For the odd software title that insists on using the full /dev/ttyUSBx 
for example, they often store their settings in a file that can often be 
edited with a text editor, where you can in effect force-feed it the 
symlink.   The fun part is finding where that is stored!)

The exact details of how to use udev rules are way to much for this 
list, but as usual, there are many websites that can furnish such info, 
plus some examples.   Has to be said though, different "flavors" of 
Linux, often store such rules in subtly different places to others.


I have zero experience of Apple Mac's.  But they use a custom version of 
BSD as their OS, that is more like Unix than Linux.  So it is likely 
some if not all of the above could work on them too. If Apple let you 
dig that deep and meddle...


Hope some of the above helps, and or gives people some ideas how to tame 
things.

73.
Dave G0WBX(G8KBV)

-- 
Created on and sent from a Unix like PC running and using free and open source software: