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On Ubuntu 10.10 (Maverick Meerkat), how can I connect a serial-to-USB device to a terminal?


I’m attempting to connect minicom to a serial device using a USB-to-serial converter. This is a PL2303, and based to what I’ve read, no further drivers are needed. The gadget is identified as a PL2303.

Minicom is something I’m new to. Is this the proper command to run? Is there anything I need to set up?

$ sudo minicom --device /dev/ttyUSB0
minicom: cannot open /dev/ttyUSB0: No such file or directory

$ sudo lsusb -v

Bus 002 Device 006: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Device Descriptor:
  bLength                18
  bDescriptorType         1

$ tail /var/log/syslog  #then removed and attached the device.
Mar 13 23:31:49 ubuntu kernel: [807996.786805] usb 2-1: pl2303 converter now attached to ttyUSB0
Mar 13 23:34:44 ubuntu kernel: [808172.155129] usb 2-1: USB disconnect, address 7
Mar 13 23:34:44 ubuntu kernel: [808172.156321] pl2303 ttyUSB0: pl2303 converter now disconnected from ttyUSB0
Mar 13 23:34:44 ubuntu kernel: [808172.156374] pl2303 2-1:1.0: device disconnected
Mar 13 23:34:52 ubuntu kernel: [808179.497856] usb 2-1: new full speed USB device using uhci_hcd and address 8
Mar 13 23:34:52 ubuntu kernel: [808179.785845] pl2303 2-1:1.0: pl2303 converter detected
Mar 13 23:34:52 ubuntu kernel: [808179.872309] usb 2-1: pl2303 converter now attached to ttyUSB0

Asked by codingJoe

Solution #1

First, use dmesg | grep tty to see if the system recognizes your device. Then run sudo minicom -s and modify the first line to /dev/ttyUSB0 in the “Serial port setup” section.

Don’t forget to “Save setup as dfl” to save the settings as default. It works for me in VirtualBox with Ubuntu 11.04.

Answered by Matej

Solution #2

You will need to set the permissions every time you plug the converter in. I use PuTTY to connect. In order to do so, I have created a little Bash script to sort out the permissions and launch PuTTY:

sudo chmod 666 /dev/ttyUSB0


P.S. Setting permissions to 777 is never a good idea.

Answered by McParty

Solution #3

I’ve been a long-time reader, but this is my first time assisting;)

I’m having the same dreadful issue with a Prolific USB to Serial adaptor, and so far Linux has been the most straightforward to get it to work.

I didn’t have to install any drivers or anything on CentOS. Having stated that,

This, however, was beneficial:

Install minicom (yum install minicom) and then configure it (minicom -s).

Then go to Serial Port Setup and change the Serial Device (Option A) to /dev/ttyUSB0 (or whatever your device file is depending on your distribution).

Then change the Bps (Option E) to 9600 and the rest should be default (8N1 Y N)

Simply save as default, then minicom, and you’re done.


Answered by Sam Greadly

Solution #4

The serial port communication applications moserial and gtkterm make it simple to check connectivity and change the settings of /dev/ttyUSB0 (or /dev/ttyUSB1!). Even if there is just one USB to RS232 adapter, the n identifier /dev/ttyUSBn can and does change from time to time! Both moserial and gtkterm will show what port designation is relevant in their respective pull down menus when selecting an appropriate port to use.

Check out for details on minicom.

Answered by Ekim

Solution #5

I was able to remedy this by dialing in as adduser *username*. Even though the only method to get it to work before was to reboot the PC or disconnect and replug the USB to Serial adapter, I never experienced this error again.

Answered by Roman

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