I doubt I’ll ever need this, but I still think it’s kind of neat. I2C is a two wire serial bus that is used in many microcontrollers to access peripheral devices using only a couple of wires. This hack notes that most modern graphics cards communicate with monitors in a similar way using a technology called “DDC”. This allows your graphics card to simply ask the monitor what resolution and scan rates it supports. The hack is to use the DDC stuff to talk to I2C peripherals. I think that’s pretty cool.