ddcutil is a command line utility for interacting with DDC/CI (Display Data Channel/Command Interface) displays on Linux. DDC/CI is a protocol that allows a computer to communicate with a monitor to adjust its settings such as brightness, contrast, and color temperature.
ddcutil can be used to query and set the various capabilities of the monitor, such as the supported VCP (Video Controller Profile) codes and the current values of these settings. It can also be used to perform automated tasks such as adjusting the monitor settings based on the ambient light level.
It provides a command line interface to the monitor’s DDC/CI feature set, allowing the user to read and change monitor settings via the I2C bus. It also provides a library of functions that can be used by other programs.
ddcutil Command Examples
1. List all compatible displays:
# ddcutil detect
2. Change the brightness (option 0x10) of display 1 to 50%:
# ddcutil --display 1 setvcp 10 50
3. Increase the contrast (option 0x12) of display 1 by 5%:
# ddcutil -d 1 setvcp 12 + 5
4. Read the settings of display 1:
# ddcutil -d 1 getvcp ALL