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

What is the universal serial bus?


The Universal Serial Bus (USB) is a computer bus used by a CPU and its peripherals to communicate to each other. In every USB communication, at least one USB host and one USB device exists. The former is the one that effectively directs the traffic flow to devices, while the latter is the one that simply answers all the host's requests.

Practically, the USB host periodically queries all connected USB devices in order to discover if they want to send a message to it. So, the host is smart enough to understand which kind of peripheral the user has connected in, and it can reconfigure the system in order to correctly manage it. This magic happens each time a USB device is first connected to a USB host, thanks to the enumeration process.

The enumeration starts by sending a reset signal to the USB device (at this stage, the data rate of the USB device is automatically determined), and after the reset, all the information of the USB device is read by the host and...