This question already has an answer here:

I've added myself to the dialout group and run

getent group dialout 

and it returns


I try to access the serial port and am getting...

[Errno 13] could not open port
/dev/ttyACM0: [Errno 13]
Permission denied '/dev/attyACM0'

So clearly I've left a step out.

marked as duplicate by N0rbert, Eric Carvalho, user535733, Zanna, vidarlo Mar 2 '18 at 15:44

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.


You need to log out and log in for the group changes to apply. (other solutions might be possible)

Lets walk trough this. I am currently not member of dialout

getent group dialout

Now I add myself

sudo usermod -aG dialout myUser

and verify

getent group dialout

However getent just looks at the configuration not at the current state (which is not updated). You can see this by looking at groups

myUser adm cdrom sudo dip plugdev lpadmin sambashare docker

no dialout here. After relogin it will work

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