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