# Can't get upload code to Arduino UNO from Ubuntu 12.04

Just finished installing arduino for the first time. I got a prompt about adding a user to a certain group. I accepted and continued. I tried to get the 'Blink' program to work. But everytime I try to upload, I get the following error;

avrdude: ser_open(): can't open device "/dev/ttyACM0": Input/output error ioctl("TIOCMGET"): Invalid argument

I started arduino as root. I know this isn't suggested. But it was the only way I could get the "SERIAL PORT" to be ungreyed. After trying to upload code and getting that error. The serial port option becomes greyed out again.

• Did I install arduino incorrectly?
• How can I correct the mentioned error?
• What can I do to keep the serial port from being greyed out?
• What is the output to the following commands: ls -l /dev/ttyACM0 and id? Oct 13, 2012 at 8:59
• Also add the output to dmesg | grep -iC5 ttyACM. Oct 13, 2012 at 9:58

This simple fix worked for me

sudo ln /dev/ttyACM0 /dev/ttySACM0

Apparently Ubuntu wants ttyS* for the usb port; it's a bit flakey about it so the ttyACM shows up then it disappears.

If your problem wasn't solved with this command:

\$ sudo ln /dev/ttyACM0 /dev/ttySACM0

maybe the usb port you are using is USB 3.0, then try plugging in a USB 2.0