Note able to detect USB Ports in terminal using command `ls /dev/ttyUSB*` getting error ls: cannot access '/dev/ttyUSB*': No such file or directory

[user146982]

NVIDIA Jetson AGX Orin Developer Kit

Hi I am trying to sent data from USB port of jetson to a C type port of external device (laptop) using python pySerial package.

But while trying to list the available usb ports using ls /dev/ttyUSB* I am getting getting error ls: cannot access ‘/dev/ttyUSB*’: No such file or directory.

But when I connected c to c cable from the following path /dev/ttyGS0 I was able to detect the c-type port at jetson.

How to detect the USB ports do we need to install any special drivers for these.

[WayneWWW]

Is there any /dev/ttyACMx node on your host?

[user146982]

Thanks for checking this

These are the following available paths

we dont have ACMx, but have AMA0

[WayneWWW]

Just to clarify… do you see any log on your host “dmesg” when you connect Jetson usb cable to it?

[WayneWWW]

And one more thing to confirm. Which port is connected on Jetson side with your cable?

[user146982]

When we connect c to c its shows valid logs for Linux for tegra

But when we connect USB to c

the same not detected

[user146982]

We tried the following port

[WayneWWW]

Are you trying to let Jetson be a USB device or a USB host?

[user146982]

we are trying to communicate from jetson USB port to laptop c type port

[WayneWWW]

Ok. If you cannot understand my question, just follow what I said.

The only port that will reveal as /dev/ttyACMx node is the type C port on Jetson.

You won’t see anything coming out on your host if you connect a type A port on Jetson.

Is it okay to understand above?

[user146982]

Thanks, does it mean that Type A ports are not meant for data transfer from jetson to external device

[WayneWWW]

You need some knowledge about how USB is working…
It is not related to Jetson but every other USB devices too.

USB type A port by its nature is a role of usb host.

Micro usb or type C usb port supports OTG, which means it could be either usb host or usb device. The role is decided during the pin connection.

If you connect type A port on Jetson and type C port on your host PC, then actually the one that plays as “usb host” is Jetson… And such /dev/ttyUSBx or ACMx shall appear on “Jetson” but not your host.
However, this is not normal usecase so I am not sure if Jetson side and your host side have sufficient driver to do this.

Thus, you should let host PC side be USB host and Jetson be USB device…

[user146982]

Got it thanks a lot