How to use the command ddcutil (with examples)

DDCUtil is a command-line tool that allows you to control the settings of connected displays via DDC/CI (Display Data Channel/Command Interface). It requires the kernel module i2c-dev to be loaded.

Use case 1: List all compatible displays

Code:

ddcutil detect

Motivation: This use case allows you to check which displays are compatible and can be controlled using DDCUtil.

Explanation:

• ddcutil - the command to invoke the DDCUtil tool
• detect - the specific command option to list all compatible displays

Example Output:

Display 1 - DELL U2415
Display 2 - LG 27UK850

Use case 2: Change the brightness of display 1 to 50%

Code:

ddcutil --display 1 setvcp 10 50

Motivation: This use case allows you to adjust the brightness of a specific display, in this case, display 1, to your desired level.

Explanation:

• --display 1 - specifies which display to target (in this case, display 1)
• setvcp - the specific command option to set a VCP (Virtual Control Panel) value
• 10 - the VCP code for brightness
• 50 - the value to set the brightness to (in this case, 50%)

Example Output:

Setting brightness of Display 1 to 50%: Success

Use case 3: Increase the contrast of display 1 by 5%

Code:

ddcutil -d 1 setvcp 12 + 5

Motivation: This use case allows you to adjust the contrast of a specific display, in this case, display 1, by a certain percentage.

Explanation:

• -d 1 - specifies which display to target (in this case, display 1)
• setvcp - the specific command option to set a VCP (Virtual Control Panel) value
• 12 - the VCP code for contrast
• + 5 - the increase in contrast by 5%

Example Output:

Increasing contrast of Display 1 by 5%: Success

Use case 4: Read the settings of display 1

Code:

ddcutil -d 1 getvcp ALL

Motivation: This use case allows you to retrieve the current settings of a specific display, in this case, display 1.

Explanation:

• -d 1 - specifies which display to target (in this case, display 1)
• getvcp - the specific command option to get the VCP (Virtual Control Panel) values
• ALL - the option to retrieve all available VCP values

Example Output:

Display 1 - DELL U2415
-----------------------
Brightness:       50%
Contrast:         80%
Color Temperature: 6500K

Conclusion:

The ddcutil command provides a convenient way to control the settings of connected displays via DDC/CI. It allows you to list compatible displays, adjust brightness and contrast settings, as well as retrieve the current settings of a display. With its ease of use and versatility, DDCUtil simplifies display management and customization.