I²C

serial communication bus that connects low-speed embedded peripheral devices

I²C (Inter-Integrated Circuit), pronounced I-squared-C, is a kind of computer bus for connecting integrated circuits and processors. It was invented in 1982 by Philips Semiconductor (which is now NXP Semiconductors).

I²C
Type Computer bus
Production history
Designer Philips Semiconductor, known today as NXP Semiconductors
Designed 1982; 42 years ago (1982)
Data signal Open-collector or Open-drain
Width data line (SDA) + clock line (SCL)
Bandwidth 0.1 / 0.4 / 1.0 / 3.4 / 5.0 Mbit/s
(depending on mode)
Protocol Serial, half-duplex