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
About the Author
About the Reviewer

How to use the audio codec

Listening to the beep generated by codecDemo_c6v0 gets very annoying after a couple of minutes, so we will try and improve matters by adding a couple of functions that will enable us to change and mute the volume. We'll also modify the code to use the beep generator to play a tune. We're limited to a fairly simple tune because the beep generator only generates audio frequencies across two octave major scales. For those who are musically minded, we define the mapping between notes (pitch) and beep frequencies, and the beep ON time (see section 6.21 of the data sheet) as well, in the codec_CS42L52.h header file. We call this recipe codecDemo_c6v1.

How to do it…

Follow the outlined steps to use the audio codec:

  1. Clone the previous recipe and name the folder codecDemo_C6v1.

  2. Open the RTE manager and add Board Support for Buttons (API) and LED (API). Click Resolve and OK.

  3. Add a function named setVolume() to the codec_CS42L52.c file:

    static void setVolume(int32_t vol) {