Arduino IDE error - avrdude: ser_open(): can't open device "/dev/ttyACM0": Permission denied
If you run Arduino IDE on Ubuntu (Arduino 1.5.7 and Ubuntu 14.04 in my case), most possibly you cannot upload to Arduino board, caused by the error of:
avrdude: ser_open(): can't open device "/dev/ttyACM0": Permission denied
ioctl("TIOCMGET"): Inappropriate ioctl for device
To fix it, enter the command:
$ sudo usermod -a -G dialout <username>
$ sudo chmod a+rw /dev/ttyACM0
Where <username> is your user name in Ubuntu, /dev/ttyACM0 is the detected device of your Arduino board.
Uploading ....