2 Teensy boards got assigned the same COM Port

Hi,
I want to have 2 Teensy boards together in one of my application and today when I tried to connect and program a new Teensy board with 1 Teensy 4.1 already connected to the USB port, the new board also got assigned the same COM port.

Rebooting the PC, uninstalling-reinstalling the driver didn't help in solving the issue. Requesting the support in solving this. Please check the image attached.

Thanks in Advance !!!

1737975360584.png
 
Before attempting any changes on your PC, can you run a couple programs to collect more info?

First is command line "teensy_ports -L". Arduino IDE installs this in {AddData}/packages/teensy/tools/teensy-tools/{version}. Normally the AddData folder is hidden on Windows, so you may need to do something special to access it. (sorry, I mostly use Linux so exactly what you do on Windows isn't something I regularly do, but there are many Windows website with info about accessing hidden folders) Might be simplest to copy teensy_ports.exe to another folder so you can easily run it from the command prompt. Running "teensy_ports -L" will give detailed info about the hardware connected.

You could also try Windows Device Manager. But it is difficult because the important info under the "advanced" tab and it only shows 1 piece of info at a time as a drop-down list. Very difficult to collect much info that way.
 
in CMD box place this then enter:
Code:
%AppData%\..\Local\Arduino15\packages\teensy\tools\teensy-tools

then dir and "cd #.#.#' folder for actual installation

There you'll find: teensy_ports.exe

Here for IDE 2 that is:
"C:\Users\YOURNAMEHERE\AppData\Local\Arduino15\packages\teensy\tools\teensy-tools\0.60.3\teensy_ports.exe"
 
Thank you for the reply.
teensy_ports -L command gave the following result:
usb:0/140000/0/4 COM3 (Teensy 4.1) Serial
usb:0/140000/0/1 COM3 (Teensy 4.1) Serial

On running teensy_ports.exe, the following details are shown:
{
"address": "usb:0/140000/0/4",
"online": true,
"label": "COM3 (Teensy 4.1) Serial",
"vid": "16C0",
"pid": "0483",
"iserial": "1604758",
"boardName": "Teensy 4.1",
"protocol": "Teensy"
}
{
"address": "usb:0/140000/0/1",
"online": true,
"label": "COM3 (Teensy 4.1) Serial",
"vid": "16C0",
"pid": "0483",
"iserial": "1663720",
"boardName": "Teensy 4.1",
"protocol": "Teensy"

}
 
This is very unusual. Something must have gone very wrong with Windows. You can reassign the COM port number, but whether it fully resolves the problem is difficult to know, because I don't understand why Windows made this mistake.

To change the COM port, use Windows Device Manager. In taskbar, search "device manager". Then under "Ports (COM & LPT)" click the device you want to change. Then click "Port Settings" tab, and then click "Advanced" button. You should see this dialog:

capture.jpg


To change the COM port, just click the drop-down list and select a different COM port number. Do not use COM1 or COM2, as those never work for USB. It must be COM3 or higher.

Hopefully this fully solves the problem? Please let us know? And if you gain any insight into why Windows made this mistake, please let us know. It is indeed very unusual and should not normally happen.
 
This is very unusual. Something must have gone very wrong with Windows. You can reassign the COM port number, but whether it fully resolves the problem is difficult to know, because I don't understand why Windows made this mistake.

To change the COM port, use Windows Device Manager. In taskbar, search "device manager". Then under "Ports (COM & LPT)" click the device you want to change. Then click "Port Settings" tab, and then click "Advanced" button. You should see this dialog:

View attachment 36776

To change the COM port, just click the drop-down list and select a different COM port number. Do not use COM1 or COM2, as those never work for USB. It must be COM3 or higher.

Hopefully this fully solves the problem? Please let us know? And if you gain any insight into why Windows made this mistake, please let us know. It is indeed very unusual and should not normally happen.
Hello Paul,

Thank you for the quick reply. It was indeed strange from Windows. I was able to change the COM port with your suggestion. Thank you
 
Windows does lots of very strange things. Doesn't surprise me - I've recently had a problem on a work machine where keyboard input was suppressed if you typed the same key again, requiring a reboot - how on earth its possible to write drivers that can fail like this defeats me...
 
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