Unable to get BBB to recognize USB Serial Device

I am running debian 9.5 2018-10-07 on a BBB

I am trying to connect a USB Serial Device (it happens to be an Arduino) to the BBB USB port so that I can control it as a serial device.
The Arduino device works fine as a serial USB device when attached to a Windows 10 USB port.

The BBB can see the device:

debian@BBB2:~$ lsusb
Bus 001 Device 002: ID 2341:0042 Arduino SA Mega 2560 R3 (CDC ACM)
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

but the BBB does not show or create any ttyUSBx device.

How do I get the BBB to create a ttyUSBx device I can access?

Is this some kind of conflict with the USB gadget function?

— Graham

UMM... looking at that "lsusb" output, it might be a /dev/ttyACM0...
(vs /dev/ttyUSBx..)

Regards,

It looks like it does show up as a ttyACM0 device, rather than a ttyUSB0 device.
Now I need to get it running, sorry for the question.
— Graham

In future you may wish to run dmesg command to see what the kernel registers the device as instead of “guessing”. HTH