PermissionError: [Errno 13] Permission denied: '/dev/ttyACM0'

Volumio Information

Volumio Version: 2,779
Hardware: Raspberry Pi 3B
DAC: Inno-Maker Hifiberry equivalent

I am trying to pipe the stream out of volumio ( mpd ) out to a python program, and then the results are ‘piped’ out of this program to the serial port (USB - /dev/ttyACM0) to an arduino which is controlling some WS2812B LED’s.

I have tried on a ‘development’ box which is a standard Raspberry build, and I have got it to work on mpd, I have loaded all the libraries which were missing on volumio.

I have also made volumio and mpd members of the dialout group.

I just cant find out why I dont have permission to the serial port.

Please help