like many people I seem to be having an issue when trying to connect my Arduino uno to the Arduino IDE in ubuntu but it seems to go beyond the usual issues that people have. I am receiving the classic avrdude: ser_open(): can't open device "/dev/ttyACM0": Input/output error error message, to rectify this I have tried following the usual advice in which you add yourself to the dialout group, reboot and it should then work however this does not work. Here's where it gets a little more interesting, using ls -l /dev/ttyACM* I get the result crw-rwx---+ 1 myusername dialout 166, 0 Jun 21 17:44 /dev/ttyACM0 . I am under the impression (purely from searching the internet, not from my own knowledge) that the + at the end of crw-rwx---+ means that the directory permissions are controlled by an ACL (though I don't really understand what these are), I try to remove the ACL from this using setfacl -b -n /dev/ttyACM0 which seems to work as when i run the ls command from earlier again it now says crw-r-x--- 1 myusername dialout 166, 0 Jun 21 17:44 /dev/ttyACM0 which is the same but without the +. After doing this the issue still persists when trying to upload a program onto Arduino, and upon rebooting and trying again, as is part of the usual fix for the issue, I am then back to square one and the + is back again. I guess what I'm looking for is a way to get rid of the + and make it stay that way every time, if anyone is able to offer any help I would be incredibly grateful!
As a side note, the Arduino works fine on Windows which I dual boot on the same computer so that can be ruled out. As a second side note, the project I'm working on is a pseudo-ambilight replica, the final step is getting Ubuntu to send the RGB colour values to the Arduino so I'm nearly there but this is causing a LOT of hassle!
