How I Wired ddcutil SwayOSD and Hyprland for Triple Monitor Brightness
External monitors don’t expose a brightness interface to the OS the same way laptop panels do, so the standard brightness keys do nothing. The fix is ddcutil, which speaks the DDC/CI protocol over i2c directly to the monitor’s firmware. I’m running Omarchy (Arch + Hyprland), which ships SwayOSD for on-screen indicators and includes a helper script omarchy-swayosd-brightness that drives it. Find your i2c buses sudo ddcutil detect Each detected monitor will show its i2c bus number. On my triple-monitor setup they came up as buses 7, 8, and 9. ...