[lubuntu] open (/dev/ttyUSB0): Permission denied : Line in use

view story

http://ubuntuforums.org – I'm trying to open a serial connection and get the following error when I try to connect either through my own account or via root using sudo: Code: cu -s 19200 -l /dev/ttyUSB0 cu: open (/dev/ttyUSB0): Permission denied cu: /dev/ttyUSB0: Line in use I am a member of the group 'dialout' Code: ls -lh /dev/ttyUSB0 crw-rw---- 1 root dialout 188, 0 Jun 24 13:15 /dev/ttyUSB0 What step am I missing? (Hardware)