[Swansea Hackspace] you have probably seen this

[Justin Mitchell]

On Wed, 2014-11-26 at 21:14 +0000, Tim Moore wrote:
> OT but I'm trying to get my usb serial port to send and receive data
> using minicom or cutecom.  Using Ubuntu 14.04
> 
> 
> I seem to think selling it that 'ttyUSB0' does the trick but nothing
> I've tied works.
> 
> 
> I've connected TX and RX together so what I type get reflected back.

Depending on the brand it will either be /dev/ttyUSB0 or /dev/ttyACM0
look at the end of the 'dmesg' command to see what device it was
assigned when it was plugged in (replug if necessary).

you will also need permission on the device, i dont know about that
ubuntu specifically but if you do an 'ls -l' on the device file you will
usually find its in group 'dialout' or 'uucp'

which ever it is, add your username to that group in /etc/group
when you login again yu should now have write permission to those files.

check to see if ModemManager is running, if it is ypu need to kill it,
and disable/uninstall it somehow, it is a bit dumb and assumes that all
serial ports have modems on the end of them, grabs the serial port and
shoves AT commands down it, so kill it off.

with all those fixed you should have more luck 
you can also use the 'serial monitor' feature inside the arduino editor,
it doesnt have to be an arduino connected, its just a serial terminal
program.