Book Image

GNU/Linux Rapid Embedded Programming

By : Rodolfo Giometti
Book Image

GNU/Linux Rapid Embedded Programming

By: Rodolfo Giometti

Overview of this book

Embedded computers have become very complex in the last few years and developers need to easily manage them by focusing on how to solve a problem without wasting time in finding supported peripherals or learning how to manage them. The main challenge with experienced embedded programmers and engineers is really how long it takes to turn an idea into reality, and we show you exactly how to do it. This book shows how to interact with external environments through specific peripherals used in the industry. We will use the latest Linux kernel release 4.4.x and Debian/Ubuntu distributions (with embedded distributions like OpenWrt and Yocto). The book will present popular boards in the industry that are user-friendly to base the rest of the projects on - BeagleBone Black, SAMA5D3 Xplained, Wandboard and system-on-chip manufacturers. Readers will be able to take their first steps in programming the embedded platforms, using C, Bash, and Python/PHP languages in order to get access to the external peripherals. More about using and programming device driver and accessing the peripherals will be covered to lay a strong foundation. The readers will learn how to read/write data from/to the external environment by using both C programs or a scripting language (Bash/PHP/Python) and how to configure a device driver for a specific hardware. After finishing this book, the readers will be able to gain a good knowledge level and understanding of writing, configuring, and managing drivers, controlling and monitoring applications with the help of efficient/quick programming and will be able to apply these skills into real-world projects.
Table of Contents (26 chapters)
GNU/Linux Rapid Embedded Programming
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Chapter 10. Serial Peripheral Interface - SPI

As we have already seen in the previous chapter, the I2C bus is widely used to connect on-board devices with the main CPU, but another bus with similar features exists: the (SPISerial Peripheral Interface (SPI). However, and opposed to the I2C bus, this bus can transfer data at higher rates than I2C, and since it's full-duplex, data transfer can take place bidirectionally at the same time. Due to these features, the SPI bus is normally used to implement an efficient data stream for multimedia applications (LCDs/video) or digital signal processing and/or telecommunications devices (Ethernet, WLAN, CAN, Serial Ports, and so on) and SD cards. However, despite this fact, it can be used to communicate with standard sensors, ADC/DAC converters, GPIOs controllers, and other similar devices.

In order to demonstrate the versatility of the SPI bus, in this chapter, we will present several different kinds of devices connected to the main CPU by this bus...