Using Com-usb serial converter need advise

Asked by Andy on 2007-05-30

I'm trying to use Com/Usb serial converter w/Ubuntu 7.04 on Compaq laptop.
When I plug converter into usb port :

tail -f /var/log/messages
May 30 13:06:06 laptop kernel: [ 1123.824000] usb 1-1: new full speed USB device using ohci_hcd and address 8
May 30 13:06:06 laptop kernel: [ 1124.028000] usb 1-1: configuration #1 chosen from 1 choice
May 30 13:06:06 laptop kernel: [ 1124.032000] ftdi_sio 1-1:1.0: FTDI USB Serial Device converter detected
May 30 13:06:06 laptop kernel: [ 1124.032000] drivers/usb/serial/ftdi_sio.c: Detected FT232BM
May 30 13:06:06 laptop kernel: [ 1124.032000] usb 1-1: FTDI USB Serial Device converter now attached to ttyUSB0
May 30 13:06:08 laptop kernel: [ 1125.768000] usb 1-1: usbfs: interface 0 claimed by ftdi_sio while 'brltty' sets config #1
May 30 13:06:08 laptop kernel: [ 1125.768000] ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0
May 30 13:06:08 laptop kernel: [ 1125.768000] ftdi_sio 1-1:1.0: device disconnected

lsusb
Bus 001 Device 009: ID 0403:6001 Future Technology Devices International, Ltd 8-bit FIFO

And , sure , there is no /dev/ttyUSB0

Any advices ?

Question information

Language:
English Edit question
Status:
Solved
For:
Ubuntu gnome-panel Edit question
Assignee:
No assignee Edit question
Solved by:
Tormod Volden
Solved:
2007-05-30
Last query:
2007-05-30
Last reply:
2007-05-30
Best Tormod Volden (tormodvolden) said : #1

Try removing the brltty package.

Andy (abrooklyn) said : #2

BRLTTY is a background process (daemon) which provides access to the Linux/Unix console (when in text mode) for a blind person using a refreshable braille display. It drives the braille display, and provides complete screen review functionality. Some speech capability has also been incorporated.

after removing brltty :

May 30 13:24:39 laptop kernel: [ 2234.680000] usb 1-1: new full speed USB device using ohci_hcd and address 11
May 30 13:24:40 laptop kernel: [ 2234.884000] usb 1-1: configuration #1 chosen from 1 choice
May 30 13:24:40 laptop kernel: [ 2234.888000] ftdi_sio 1-1:1.0: FTDI USB Serial Device converter detected
May 30 13:24:40 laptop kernel: [ 2234.888000] drivers/usb/serial/ftdi_sio.c: Detected FT232BM
May 30 13:24:40 laptop kernel: [ 2234.888000] usb 1-1: FTDI USB Serial Device converter now attached to ttyUSB0

Andy (abrooklyn) said : #3

Thanks Tormod Volden, that solved my question.

danield (danield-andrew) said : #4

Is there another way to solve this problem? I'm developing software for blind users which uses a serial-usb slate and stylus, and I'd love to not cripple the brltty support in the process :)
Thanks for your time.

Tormod Volden (tormodvolden) said : #5

Danield, please file a bug on the brltty package, and refer to this ticket.

Wiktor Wandachowicz (siryes) said : #6

There is already a bug reported for linux-source-2.6.20 package Ubuntu:
https://bugs.launchpad.net/ubuntu/+source/linux-source-2.6.20/+bug/122834

It seems like one of udev rules installed as part of brltty package interferes with normal operations of said "Com-usb serial converter". Just commenting out a line in /etc/udev/rules.d/85-brltty.rules, like:

# SYSFS{idVendor}=="0403", SYSFS{idProduct}=="6001", RUN+="/lib/brltty/brltty.sh -b ht -d usb:"

restores the desired behaviour, ie. /dev/ttyUSB0 is not removed and the converter should work. Please note the # at the beginning of the line - this way udev will ignore this rule.

In order to apply this change you may also need to restart your computer or manually kill all running brltty instances using the terminal command, like:
$ sudo killall brltty

At least this did the trick for me, without uninstalling otherwise useful brltty package (think visually impaired/blind users).

halestorm (dave-halestorm) said : #7

Could there be another solution? I am having the same problem (assigning a /dev/xxx to a FTDI USB device) but I do not have brltty installed.