Arduino Workshop, 2nd Edition

19 Data Buses

In this chapter you will

• Learn about the I²C bus
• See how to use an EEPROM and a port expander on the I²C bus
• Learn about the SPI bus
• Find out how to use a digital rheostat on the SPI bus

An Arduino communicates with other devices via a data bus, a system of connections that allows two or more devices to exchange data in an orderly manner. A data bus can provide a connection between the Arduino and various sensors, I/O expansion devices, and other components.

The two major buses of most importance to the Arduino are the Serial Peripheral Interface (SPI) bus and the Inter-Integrated Circuit (I²C) bus. Many useful sensors and external devices communicate using these buses.

The I²C Bus

The I²C bus, also known as the Two-Wire Interface ...