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).

Piet, PE0PWA (ham radio call).

"P. vanderWal" wrote

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

For Debian you usually have to be part of the "dialout" group to have access to the serial ports.

Henry

Same for Slackware and possibly others. Always catches me out, despite doing quite a lot of this sort of stuff.