By using a protocol called Inter-Integrated Circuit (I2C), the Wire library greatly reduces the number of wires required to connect devices. The protocol is supported on all Arduino boards ...

The I2C/TWI pins on the Micro are on D2 and D3. For Arduino beginners, these two boards are nearly interchangeable, especially when used in simple circuits like the Arduino's built-in examples.

[gioblu] wasn’t impressed with the complications of I2C. He thought one-wire was too proprietary, too complicated, and its Arduino implementations did not impress. What he really wanted was a ...