No serial device found for arduinoUno r3


I am trying to get serial communication with my new arduinoUno r3 board, over the USB cable. When I plug in the usb it shows

[20123.221673] usb 6-1.8: new full-speed USB device number 5 using ehci-pci
[20123.310411] usb 6-1.8: New USB device found, idVendor=2341, idProduct=0043
[20123.310416] usb 6-1.8: New USB device strings: Mfr=1, Product=2, SerialNumber=220
[20123.310418] usb 6-1.8: Manufacturer: Arduino (
[20123.310420] usb 6-1.8: SerialNumber: XXXXXXXXXXXXXXXXXXXX

But nothing new shows up in /dev/tty*
Other forum posts mention the ftdi_sio.ko and usbserial.ko kernel drivers, but I have those loaded. I guess these modules are for the boards with ftdi, while uno-r3 does not have that. Which kernel modules do I need for this board?


What operating system are you using ?

I have never needed drivers with Linux (Xubuntu or Puppy Linux).


Turns out linux needs the cdc-acm module

Symbol: USB_ACM [=m]
Type  : tristate
Prompt: USB Modem (CDC ACM) support
    -> Device Drivers
      -> USB support (USB_SUPPORT [=y])
        -> Support for Host-side USB (USB [=y])

With this driver the /dev/ttyACM0 appears, and I can continue.

The 'modem' bit got me confused so I didn't try it earlier :)

What version of Linux were you using that did not include that module automatically ?

It would be useful to others to give more details of your problem and solution.