Book excerpt: Technology is constantly changing. New microcontrollers become available every year and old ones become redundant. The one thing that has stayed the same is the C programming language used to program these microcontrollers. If you would like to learn this standard language to program microcontrollers, then this book is for you! ARM microcontrollers are available from a large number of manufacturers. They are 32-bit microcontrollers and usually contain a decent amount of memory and a large number of on-chip peripherals. Although this book concentrates on ARM microcontrollers from Atmel, the C programming language applies equally to other manufacturers ARMs as well as other microcontrollers. The book features: Use only free or open source software; Learn how to download, set up and use free C programming tools; Start learning the C language to write simple PC programs before tackling embedded programming -- no need to buy an embedded system right away!; Start learning to program from the very first chapter with simple programs and slowly build from there; No programming experience is necessary!; Learn by doing -- type and run the example programs and exercises; Sample programs and exercises can be downloaded from the Internet; A fun way to learn the C programming language; Ideal for electronic hobbyists, students and engineers wanting to learn the C programming language in an embedded environment on ARM microcontrollers.