Remove the USB cable from your computer. Wait 10 to 15 seconds, then plug it back in.
Open a terminal.
type dmesg | tail
You should see what the cable is and where it got connected.
For example
# dmesg | tail
[52106.249452] cp210x 1-1:1.0: device disconnected [52109.834253] usb 1-1: new full-speed USB device number 8 using xhci_hcd [52109.976525] usb 1-1: New USB device found, idVendor=10c4, idProduct=ea60, bcdDevice= 1.00 [52109.976531] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [52109.976536] usb 1-1: Product: CP2102 USB to UART Bridge Controller [52109.976540] usb 1-1: Manufacturer: Silicon Labs [52109.976544] usb 1-1: SerialNumber: 0001 [52109.980356] cp210x 1-1:1.0: cp210x converter detected [52109.982965] usb 1-1: cp210x converter now attached to ttyUSB0
It tells me that my USB device is made by Silicon Labs, it's a cp210x converter and it's attached to ttyUSB0 which is a device, so it's location is: /dev/ttyUSB0
If for some reason the device is different, in what follows substitute what dmesg told you for what I wrote.
Now list in long format /dev/ttyUSB0 using ls -l
# ls -l /dev/ttyUSB0 crw-rw---- 1 root uucp 188, 0 Jan 13 12:39 /dev/ttyUSB0
It says that this device is owned by "root" and is in the group uucp and both root and anyone in uucp have read and write (rw) privledges.
Now see if I'm in that group. So I change back to my user prompt.
type exit in terminal, then you should have user prompt $.
Type in "groups" to see what groups you're in (no quotes, just what is inside the quotes!)
$ groups cups video uucp wheel djringjr
I'm in those groups - uucp is one of the groups.
The group of /dev/TTYUSB0 is probably different in Ubuntu, so adjust what I am saying to match what you got when you listed /dev/ttyUSB0 in long format. Your user has to be in the group that owns ttyUSB0.
If it isn't you have to put your user into that group.
Back up to root admiinistrator privledges.
sudo su or if you don't have sudo you can just enter su or su root and give the root password.
sudo su
#
Now we have the # prompt, we are root now.
Enter "gpasswd -a yourusername uucp"
Where yourusername is your user name. Mine is djringjr so do this:
# gpasswd -a djringjr uucp Adding user djringjr to group uucp
Now reboot your computer and you'll have access to /dev/USB01
Sometimes just logging out and back in will recognize the device, but rebooting always does.
73 David N1EA