What a great idea. It should be obvious and easy but DDC commands are hard to find and should be documented better.

I have a Dell U4323QE in the office and look forward to trying this out. I wondered if it was the same DDC commands so I googled a little and found this gist (concerning DDM):

https://gist.github.com/nebriv/cb934a3b702346c5988f2aba5ee39...

Which has the very useful comment:

https://gist.github.com/nebriv/cb934a3b702346c5988f2aba5ee39...

Which states:

#define LUMINANCE 0x10 #define CONTRAST 0x12 #define VOLUME 0x62 #define MUTE 0x8D #define PBP 0xE9 #define SWAP_USB 0xE7 #define SWAP_INPUT 0xE5 #define INPUT 0x60 #define SUB_INPUT 0xE8 #define INPUT_ALT 0xF4 // alternate address, used for LG exclusively? #define STANDBY 0xD6

I much prefer simple DDC commands over using something like Synergy or Barrier. I think it is a much cleaner solution.