As many of us who love DIY and building projects, we have in a drawer a Raspberry Pi or Arduino.
On a cold and rainy day. I was at my PC, opened the drawer and found the forgetten Raspberry Pi Pico W, bought for some project but forgot there.

So the time has come to make new things whit my Pico W.

I’m Linux user for several reason and of course, I want use it for the most of my tasks. I tried to connect the Pico W to my PC with Thonny but I noticed that I had no connection to the Pico.

The error was this one:

Unable to connect to /dev/ttyACM0: [Errno 13] could not open port /dev/ttyACM0: [Errno 13] Permission denied: ‘/dev/ttyACM0’

The solution I found for my problem is this:

ls -l /dev/ttyACM0

in the terminal I run this command: ls -l /dev/ttyACM0 in order to see which group owns the device /dev/ttyACM0.

In most cases the group is dialout but it can be different too.

user@linux:~$ ls -l /dev/ttyACM0
crw-rw—- 1 root dialout 166, 0 Nov 24 07:57 /dev/ttyACM0

The next step is to add your user to that group. Do this with the following command:

sudo usermod -a -G dialout username

After that, a reboot and everything should work.