How do I connect to TTY/COM (/dev/ttyUSB0)?

  • I am running Ubuntu for the first time by booting from a USB drive. Now I have plugged in a USB-to-serial converter which has been recognized and automatically added as /dev/ttyUSB0.

    How do I access /dev/ttyUSB0?

  • Douglas

    Douglas Correct answer

    9 years ago

    Use one of screen's lesser known features:

    screen /dev/ttyUSB0

    if you need to specify the baud rate, add it after the serial device. eg, for 57600 baud: `screen /dev/ttyUSB0 57600`

    Note that if you want to detach from the terminal and CTRL-D isn't cutting it, use CTRL-A then k to kill screen. I had to use this with the TTY at ~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty provided by Docker for Mac. CTRL-A then d will work too, but will leave your screen session running, which may or may not be what you want.

  • you can use ckermit also. It should be in the repository. After installing it create a file in your home directory called .mykermrc then add the 5 following lines:

    set line /dev/ttyUSB0   
    set flow-control none  
    set carrier-watch off  
    set speed 115200  

    parameters can be adjusted as necessary.
    save the file.
    to start it

    sudo kermit 
  • You can use putty. Its an ssh/serial/telnet client for Windows and Linux. You can download it from

  • You could use tio - a simple tty terminal I/O application:

    tio /dev/ttyUSB0


  • You can use picocom, it is a minimal dumb-terminal emulation program. Basic usage is something like this (change 11520 to the desired baud rate):

    $ picocom -b 115200 /dev/ttyUSB0

    You have all the options you may want from a dumb-terminal program, like stop bits, parity, local echo, carriage return / line feed / backspace / delete / tab translation, X/Y/Z-modem and ASCII transfer integration, etc.

    See man picocom and picocom --help for further information.

  • I was using puTTY to connect to the serial ports. But don't forget to add your user to dialout: sudo adduser <username> dialout then reboot the system.

    After that, you can use puTTY for serial connections such as /dev/ttyUSB0.

    it is actually enough to simply log out and back in again.

  • Needed Mint 17.1 to talk to my Arduino, after a little chasing around, it turns out that your user must be part of the dialout group to use the tty. This should apply to Ubuntu as well. You can do so either by running the command:

    sudo usermod -a -G dialout username

    Or graphically, by using:

    Administration → Users & Groups → Manage Groups

    In which case you would go to the line for dialout, check the properties to ensure that username is ticked, if not username must be added.

    This worked for me and by the look of lots of posts others have had the same problem.

    -1 for `sudo gedit /etc/group`. Don't. Just don't. Learn how to add a user to a group using `usermod` or `adduser` for example. And your post is more of a comment rather than an answer to the question, because you don't actually show how to connect.

  • Using Lucid and a Dynamode USB to RS232 cable:

    Plugged it in
    ran kermit
    set line /dev/ttyUSB0    <<-- mind the capitals/lowecase
    set speed 9600

    and successfully connected to an RS232 port on an OpenVMS server.

  • Or

    minicom -D /dev/ttyUSB0

    If you need to configure it first, then

    minicom -s

    If you're wondering where's the meta key in MacOS, you will need to plan an escape. For other options, -h for help.

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Content dated before 6/26/2020 9:53 AM