My app cannot use USB when ordinary user

neok · 2008-03-05 11:18:30

Hi,

I have written an application that controls a USB Phidget servo via libusb, but when I log is as an ordinary user my app cannot communicate with the servo. As far as I can tell the problem is that when an ordinary user, my app cannot use libusb. But I can generally use other USB devices like flash drives or digital cameras.

It may be a matter of adding my self to a group but can't figure out which (there seems to be no usb group in /etc/group.

Any ideas/hints please?

My thanks in advance.

whompus · 2008-03-05 12:26:36

Create the group and add your users to it

groupadd usb
gpasswd -a <user> usb

neok · 2008-03-05 14:54:21

whompus wrote:

Create the group and add your users to it
groupadd usb
gpasswd -a <user> usb

OK thanks whompus, I tried it but it doesn't work. Seems it something else, hope I have a good guess eventually...

whompus · 2008-03-05 17:04:53

It might be a udev rules setting as I had to change a rule to access my mobile phone as a user, it's a usb phone but needed a tty rule (I think). I don't know enough about this to help you.

neok · 2008-03-05 18:04:53

whompus wrote:

It might be a udev rules setting as I had to change a rule to access my mobile phone as a user, it's a usb phone but needed a tty rule (I think). I don't know enough about this to help you.

I know even less...;) but I found out what I did wrong, rather silly in retrospect but as I said, never had to fiddle with udev: I added the usb group but did not add GROUP="usb" to the udev usb_device rule. Now its OK, thank for the tip!

Arch Linux

#1 2008-03-05 11:18:30

My app cannot use USB when ordinary user

#2 2008-03-05 12:26:36

Re: My app cannot use USB when ordinary user

#3 2008-03-05 14:54:21

Re: My app cannot use USB when ordinary user

#4 2008-03-05 17:04:53

Re: My app cannot use USB when ordinary user

#5 2008-03-05 18:04:53

Re: My app cannot use USB when ordinary user

Board footer