I'm using an Ubuntu 14.04 and I'm having trouble with port permission for /dev/ttyACM0 . Every time I plug in my arduino uno board to my laptop, I face problems uploading code to the board beacuse I get a 'Permission Denied' error.
The problem was resolved when I gave the port Read-Write access with
sudo chmod 666 /dev/ttyACM0, but only temporarily. The permission error reoccurs when I disconnect and reconnect the arduino board.
I followed this thread to make the change permanent by adding my username to the dialout group, but it didn't work.
Is there any other way to resolve this issue??