Arduino program only works when run as root Uploading simple sketches seems to work when I run the Arduino program as root (sudo). I would like to run it as a regular user. Has anyone faced the same problem before and fixed it?

Here is what I obtained from lsusb:

$ lsusb
Bus 002 Device 022: ID 2341:0043 Arduino SA Uno R3 (CDC ACM)


And the Arduino program identifies it as /dev/ttyACM0. Here are its permissions: 

$ ls -l /dev/ttyACM0 
crw-rw---T 1 root dialout 166, 0 Mar 14 22:03 /dev/ttyACM0


Here is the output from id

groups=1000(abhiram),20(dialout),24(cdrom),25(floppy),29(audio),
30(dip),44(video),46(plugdev),105(scanner),110(bluetooth),112(netdev)


When I upload an sketch from the examples, as a regular user, I encounter this error:

avrdude:stk500_recv(): programmer not responding


Any suggestions are welcome.
The easiest solution is to add yourself to the dialout group.

First make a note of the output from id. Save it in file (not in /tmp as that gets cleaned out on a reboot). If you look at the output, you'll notice that your user is signed up for several groups and those groups represent extra privileges on the system. By default your Arduino is assigned to the group dialout because it registers as a serial interface and in the old days these were often used to ... dial out, using a modem.

To add yourself to the dialout group, issue the following command:

sudo usermod -a -G dialout $USER


Don't forget the -a flag (for appending groups rather than replacing) or you will have entirely different problems. This is the reason for making a copy of the id output to a file, so in case you do mess up at least you know what your user was configured like before.

Then log out and log in and it should work from that point.

Optionally you can double check the output for id against the output you saved before.