[eurasiantiger]

On the contrary, any device which has DDC support and a VGA, DVI or HDMI output will have an i2c pin in the connector. Even DP carries i2c in its aux channel. https://hackaday.com/2014/06/18/i2c-from-your-vga-port/

[galangalalgol]

that is a cool hack, but its just using i2c to talk to an atmega and have it do the gpio. You could just as well use the atmega from usb. Or an esp over wifi.