Skip to Content
Arduino Cookbook, 3rd Edition
book

Arduino Cookbook, 3rd Edition

by Michael Margolis, Brian Jepson, Nicholas Robert Weldin
April 2020
Intermediate to advanced
795 pages
17h 43m
English
O'Reilly Media, Inc.
Content preview from Arduino Cookbook, 3rd Edition

Communicating Using I2C and SPI

13.0 Introduction

The I2C (Inter-Integrated Circuit) and SPI (Serial Peripheral Interface) standards were created to provide simple ways for digital information to be transferred between sensors and microcontrollers such as Arduino. Arduino libraries for both I2C and SPI make it easy for you to use both of these protocols.

The choice between I2C and SPI is usually determined by the devices (for example, sensors, actuators, other boards) you want to connect. Some devices provide both standards, but usually a device or chip supports one or the other.

I2C has the advantage that it only needs two signal connections (clock and data) to Arduino, while SPI needs four. With I2C, you also get acknowledgment that signals have been correctly received. The disadvantages are that the data rate is slower than SPI and data can only be traveling in one direction at a time, lowering the data rate even more if two-way communication is needed. It is also necessary to connect pull-up resistors to the connections to ensure reliable transmission of signals (see the introduction to Chapter 5 for more on pull-ups). The exact value of an I2C pull-up resistor varies depending on a number of factors, such as the length and type of wire you are using. Generally, you will probably find that 4.7K works best.

If you are connecting to an I2C device that’s on a breakout board or shield, it’s possible that the manufacturer has included pull-ups. You won’t know for sure, so you ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

AirBnbBlueOriginElectronic ArtsHomeDepotNasdaqRakutenTata Consultancy Services

QuotationMarkO’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
QuotationMarkI wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
QuotationMarkI’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
QuotationMarkI'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Mark W.
Embedded Software Engineer

You might also like

Arduino for Arduinians

Arduino for Arduinians

John Boxall
Getting Started With Arduino, 4th Edition

Getting Started With Arduino, 4th Edition

Massimo Banzi, Michael Shiloh

Publisher Resources

ISBN: 9781491903513Errata Page