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

Getting access to I2C devices


Now we are ready to manage real I2C devices. We can find tons of supported devices into the Linux kernel tree whose are usually grouped according to their specific operations so, for instance, all I2C real-time clock chips are under the directory drivers/rtc/ while I2C EEPROMs are under directory drivers/misc/eeprom/, and so on of the Linux's source repository.

In the next section we're going to see several different kinds of devices all connected to the main CPU through the I2C bus, also we're going to use different embedded kits to test them, but as said before, every commands can be easily repeated on every GNU/Linux based boards with a similar configuration.

EEPROM, ADC and IO Expander

As first example we're going to use the following development board carrying five I2C devices:

Note

The device can be purchased at the following link (or by surfing the Internet): http://www.cosino.io/product/i2c-sensors-board

On this board we have an EEPROM, an ADC, a DAC...