Fix Raspberry PI "VCHI initialization failed" error:
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You will get the error for the "vcgencmd" command when a new user is set up on the raspberry pi, it will look like this:
#VCHI initialization failed

Input this command to add your user to the video group to enable use of the "vcgencmd" command by:
sudo usermod -aG video emperor_penguin_of_japan

Replace emperor_penguin_of_japan with your current user.
You will need to log out then log back end for changes to take effect.

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Source: https://chewett.co.uk/blog/258/vchi-initialization-failed-raspberry-pi-fixed/
Date: April 29th, 2021