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).

Type Computer bus
Production history
Designer Philips Semiconductor, known today as NXP Semiconductors
Designed 1982; 40 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