Book Image

ARM® Cortex® M4 Cookbook

By : Mark Fisher, Dr. Mark Fisher
Book Image

ARM® Cortex® M4 Cookbook

By: Mark Fisher, Dr. Mark Fisher

Overview of this book

Embedded microcontrollers are at the core of many everyday electronic devices. Electronic automotive systems rely on these devices for engine management, anti-lock brakes, in car entertainment, automatic transmission, active suspension, satellite navigation, etc. The so-called internet of things drives the market for such technology, so much so that embedded cores now represent 90% of all processor’s sold. The ARM Cortex-M4 is one of the most powerful microcontrollers on the market and includes a floating point unit (FPU) which enables it to address applications. The ARM Cortex-M4 Microcontroller Cookbook provides a practical introduction to programming an embedded microcontroller architecture. This book attempts to address this through a series of recipes that develop embedded applications targeting the ARM-Cortex M4 device family. The recipes in this book have all been tested using the Keil MCBSTM32F400 board. This board includes a small graphic LCD touchscreen (320x240 pixels) that can be used to create a variety of 2D gaming applications. These motivate a younger audience and are used throughout the book to illustrate particular hardware peripherals and software concepts. C language is used predominantly throughout but one chapter is devoted to recipes involving assembly language. Programs are mostly written using ARM’s free microcontroller development kit (MDK) but for those looking for open source development environments the book also shows how to configure the ARM-GNU toolchain. Some of the recipes described in the book are the basis for laboratories and assignments undertaken by undergraduates.
Table of Contents (16 chapters)
ARM Cortex M4 Cookbook
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Configuring GPIO ports


The recipe, helloBlinky_c1v0, that we met in Chapter 1, A Practical Introduction to ARM Cortex, uses the LED_On() and LED_Off() functions to switch the LEDs. These functions are defined in a file named LED_MCBSTM32F400.c, which is automatically included in our project if we select LED (API) Board Support when configuring our project using the RTE manager. Let's write another LED program and then take a closer look at LED_MCBSTM32F400.c.

How to do it…

To configure the GPIO ports follow the outlined steps:

  1. Create a folder named countBlinky_c3v0 and a project named countBlinky; use the RTE manager to select Board Support for the LED (API).

  2. Enter the following source code in file named countBlinky.c and add this to the project:

    /*---------------------------------------------
     * Recipe:  countBlinky_c3v0
     * Name:    countBlinky.c
     * Purpose: LED Counter
     *---------------------------------------------
     *
     * Modification History
     * 03.05.15 Created
     * 16.12.15 Updated (uVision5...