Combining the Raspberry Pi with the power of the open source Arduino platform, this book will walk you through several projects for building electronic sensors and introduce you to software that will record this data for later use.
While the RPi can be used without any additional hardware (except perhaps a power supply of some kind), it won't be much use as a general computer. As with any normal PC, it is likely you will need some additional hardware.
CHAPTER 1: INTRODUCTION TO RASPBERRY PI THE EVOLUTION OF RASPBERRY PI 2 THE UNIQUE FEATURES: MODEL A MODEL A+ MODEL B MODEL B+ SHOULD YOU BUY THE LATEST RASPBERRY PI 2, IF YOU HAVE PREVIOUS MODELS? GETTING STARTED BOOTING AND CONNECTIONS A FEW THING
