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 1-Wire Bus?


The one-wire (1-Wire) bus is a half-duplex, single-master, multi-slave, asynchronous serial data bus designed to work with one wire only. In reality, for electrical reasons, the wires are at least two: one wire that carries a low-speed data signal with the power supply (data/power line) and the other one that is the ground (GND). However, despite this feature, most devices have three wires: the data signal, the GND, and the power supply (Vcc).

Tip

You should remember that half-duplex communication is when transmitting and receiving are not at the same time on the bus (the data can flow in one direction only), while asynchronous means that no clock is sent along with the data.

When a device has two wires only, it must include an in-built energy-storage mechanism (usually a capacitor) to store charge to power itself during periods when data is really exchanged. The device takes its power from the data pin instead of the regular power pin, and due to this reason, this...