Turn off hdmi RPI 4B bookworm

Question

I want to find a way to turn on and off a HDMI connected display with simple command. In past it used to be something with xrandr, but due to linux forever evolving, it is not working anymore.

i tried : sudo xrandr --output XWAYLAND0 --off > not working sudo vcgencmd display_power 0 > not working sudo xset dpms force off > not working

sudo or non sudo is same result... what it seems is that instead of something like HDMI-0, there is XWAYLAND0 as name of display

talking to chat gpt and searching the internet... like forever. This is second day i am trying to figure this out... Every time i am looking for a simple answer to a simple problem i am getting reminded why i hate linux so much... there just cannot be a simple solution, everything need to be overcomplicated. (rant)

Answer 1

As you're no doubt aware, Wayland is new. In LinuxWorld, new often equates to poorly documented. I wonder if you might have better luck using the older, but better-documented graphics system: X??

I run all of my systems headless, but AIUI you can switch from Wayland to X using the raspi-config utility. Start raspi-config from the command line by entering the following:

sudo raspi-config  

When the menu presents, select 6 Advanced Options, and the sub-menu will list more options including A6 Wayland Switch between X and Wayland backends. Switch to X, and your older commands should (may?) work.

There are also a couple of "lower-level" solutions that may allow you to keep Wayland if you're inclined:

vcgencmd display_power 0  # `0` turns OFF; `1` turns ON

alternatively, install cec-utils & use that:

sudo apt update
sudo apt install libcec3 cec-utils
echo 'standby 0' | cec-client -s -d 1    # turns OFF
echo 'on 0' | cec-client -s -d 1         # turns ON

REFERENCES (all obtained via search engine `raspberry pi HDMI interface`):

1. How to automatically turn off and on your monitor from your Raspberry Pi
2. Using HDMI-CEC on a Raspberry Pi