It's insane how monitor software hasn't developed an inch from the 90s. How hard...

fibonachos · on June 12, 2020

This actually exists, and it’s called DDC/CI: https://en.m.wikipedia.org/wiki/Display_Data_Channel

I only recently learned about it myself while setting up a new monitor and asking myself wtf is this DDC/CI setting in the menu.

joelby37 · on June 12, 2020

Thanks for the hot tip! I've been struggling with my monitor's menu buttons, but after reading your comment I found the macOS tool MonitorControl, which works perfectly.

6AA4FD · on June 12, 2020

I can control laptop brightness with `/sys/class/backlight/foo`, and my asus external monitor advertises capabilities over hdmi with `modprobe i2c-dev` and then `ddcutil capabilities`. Apparently this is governed by something called MCCS. You can find more info on the arch wiki.

mixmastamyk · on June 12, 2020

I have a script with ddccontrol to change brightness of my external monitor:

    ddccontrol -r 0x10 -w ${NUM}0  dev:/dev/i2c-${DEV_NUM}

The internal:

    BACKLIGHT_PATH="/sys/class/backlight/intel_backlight/brightness"
    sh -c "echo ${NUM} > $BACKLIGHT_PATH"

The numbers are a slightly different scale, so I adjust them in the script.