Read the statement by Michael Teeuw here.
Turn HDMI on/off problem
I know I am going to be flamed for asking this, but here goes…
I am trying to implement a PIR sensor on a Raspi 4b to turn on the HDMI output when activated. I have read page up and down of this issue and have seen different possible solutions, but nothing that works for me.
I can use tvservice -o to turn off HDMI just fine. When I use tvservice -p again, the monitor turns on, but remains only with backlight.
I have read something about adding a resistor on the powercable for the monitor, but have anyone found a solution to this? Is it because I am using a specific monitor or is this a general problem?
you may have to use one of the other methods - every device is a little odd.
I found a solution for my monitor SAMSUNG S24F354 using:
DISPLAY=:0 xset dpms force on
DISPLAY=:0 xset dpms force off
This seems to work right now from the shell. Turns the monitor instantly off/on. Last night when trying with the PIR script, it didn’t work however, returning an error when calling shell scripts: the server was lacking dpms. This must be because DPMS was turned off as a part of the MagicMirror configuration.
I have a fresh install right now and just verified that these commands actually works. Now to get the PIR sensor working with the shell scripts.
If someone want to test, il will try to code it in my pir module
@MilkShake dpms is off because u asked to turn off screensaver.