I have a Raspberry Pi 3B, a Raspberry Pi 4B, and an LG monitor. When I connect the PI3 to the monitor and type: export DISPLAY=:0;xrandr --output HDMI-1 --brightness 0, it totally blanks the display, which is exactly what I want. When I connect the PI4 to the same monitor, this command does nothing. It just returns without error and doesn't change the screen. All the posts on brightness for PI4 recommend using ddccontrol/ddcutil, and after experimenting with that, it appears that my monitor doesn't support it.
So my question is: It is obviously possible for a Raspberry Pi to control the brightness on my monitor exactly how I want it. I really want to use the PI4 because it is much faster and my application is taxing the PI3. So how can I get the PI4 to dim the screen like the PI3 does? If necessary, I am willing to try to do some coding to port whatever infrastructure exists on the PI3 to the PI4. At least getting a technical reason for the difference in behavior between the PI3 and PI4 would be helpful.
Thank you so much for your help.
So my question is: It is obviously possible for a Raspberry Pi to control the brightness on my monitor exactly how I want it. I really want to use the PI4 because it is much faster and my application is taxing the PI3. So how can I get the PI4 to dim the screen like the PI3 does? If necessary, I am willing to try to do some coding to port whatever infrastructure exists on the PI3 to the PI4. At least getting a technical reason for the difference in behavior between the PI3 and PI4 would be helpful.
Thank you so much for your help.
Statistics: Posted by raspberrypi19 — Thu Dec 19, 2024 6:17 pm