Chapter 17. Data Buses

In this chapter you will

Learn about the I²C bus
Understand how to use an EEPROM (electrically erasable read-only memory) and a port expander on the I²C bus
Learn about the SPI bus
Learn 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 allow 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 bus (I²C). Many useful sensors and external devices communicate using these buses.