Comment by crote

Comment by crote a day ago

2 replies

Modern monitors don't even use an EEPROM chip for EDID anymore. The I2C bus is hooked up to a microcontroller inside the monitor, which allows it to implement Display Data Channel. This way you can tune things like display brightness and color profile from an application running on the computer, instead of messing around with the monitor's OSD.

Tools like ddcutil aren't very well-known, but they can be quite useful if you want to do something like DIYing a KVM switch by just having the PC tell the monitor to switch to a different input!

Crespyl 17 hours ago

> DIYing a KVM switch by just having the PC tell the monitor to switch to a different input!

I made a tiny contribution to the ddcutil-db database when I did exactly that. My monitor wasn't supported initially, but it wasn't hard to use the utils and templates to poke around and find the correct addresses for basic settings and input switching.

It was a nice afternoon's work to get it all working.

nyanpasu64 18 hours ago

Do any monitors use the I2C multi-peripheral feature to allow both DDC communication and an I2C EEPROM to exist at different addresses on the same bus? Or is it cheaper to integrate functionality into a controller chip? (Though DP tunnels EDID over the aux bus, and (I assume) doesn't use an EEPROM to begin with.)