Re: TtyUsb Yocto Issue

[Paul Eggleton <paul.eggleton@linux.intel.com>]

Hi Jawad,

On Tuesday 08 October 2013 06:43:18 Jawad Hassan wrote:
> We're trying to access the USB serial port using rxtx on a java application
> on Yocto. The problem is that we're unable to list out any ports on the
> Nitrogen Lite board, we think this could be a permissions issue, if anyone
> has been able to do this or any resources that can help us in getting this
> done.

It's hard to say for sure without further details, but assuming the device
nodes actually exist in /dev and it's a typical device permissions issue there
are two options:

1) Look at the /dev/ttyUSB* device nodes that exist and see if there is
already a group assigned with write access; if so you just need to ensure the
user you are running as is a member of that group.

2) Create a udev rule to set the device permissions correctly. This would be a
matter of creating a recipe to install an extra file to /etc/udev/rules.d that
assigned the desired permissions. There are lots of HOWTOs out there on the
web for this, e.g.:

http://sourceforge.net/apps/mediawiki/gizmod/index.php?title=HOWTO_-_Setting_Input_Device_Permissions_-_Creating_a_udev_Rule

Cheers,
Paul

-- 

Paul Eggleton
Intel Open Source Technology Centre