[fpc-pascal] How to use serial or usb-ports in linux

Christo christo.crause at gmail.com
Sun Sep 6 19:02:46 CEST 2015


On Sun, 2015-09-06 at 12:40 +0200, Sven Barth wrote:
> Am 06.09.2015 12:34 schrieb "P. vanderWal" <p.wal1 at quicknet.nl>:
> >
> > Hello all,
> >  
> > I wrote a program to control a hobby milling machine.(Profiler, see
> Elektor-forum). The programm is written in fpc-pascal and using
> synaser in the windows version for control of the serial port(s).
> > Now I want to use the program in Debian 8... and or Ubuntu 15...
> Compiling and running the present version gives "no permission" for
> the serial/usb ports.
> > Please advise how to get the program running with these ports.
> (lazarus 1.2.4 fpc 2.6.4).
> 
> You need to run your program either as root or ensure that the user
> you run as is allowed to use the ports. 
> You can check that by doing a "ls -l /dev/tty*", which will list the
> user and group of the ttys as well as the permissions. With "groups"
> you should be able to list what groups your user is part of and
> whether one of those matches the group of the ports you try to access.
> 
> Regards,
> Sven
> 

A different flavour of what Sven recommended is to write a udev rule
which adds the permissions to any (or according to some filter rules)
usb device on the fly.  This is particularly useful if the kernel
assigns different names to different devices.  I have the following rule
in /etc/udev/rules.d/50-permissions-on-unclaimed-usb-devices.rules:

 SUBSYSTEM=="usb", ATTRS{bDeviceClass}=="ff", ACTION=="add",
GROUP="groupname", MODE="0664" 

Regards,
Christo




More information about the fpc-pascal mailing list