Basics

The I²C (Inter-Integrated Circuit) protocol, referred to as I-squared-C, I-two-C, or IIC) is two wire serial communication protocol for connecting low speed peripherals to a micrcontroller or computer motherboard. You can go through I²C /TWI Basics tutorials to understand how I²C works.

Registers

TWBR

TWCR

TWSR

TWDR

Practical Example

AVR Interfacing: RTC DS1307