Introduction to the Second Edition In the six years since I completed the first manuscript of this book, there has been a tremendous evolution of the PIC24 architecture and all the supporting set of tools and documentation. What seemed like a promising, if only embryonic, new product line has become one of the main driving forces in Microchip Technology's portfolio. The number of different models available has long passed the 100 mark. It's been growing up toward larger and larger memory sizes and more complex devices as well as down to smaller, simpler devices in tiny packages and with minuscule power consumption figures where, once upon a time, it used to be the undisputed sole domain of the smallest of the 8-bit PIC ® architectures. Back then, when looking for evaluation boards, there was only one choice: the Explorer16 and that is what I had to use for the first edition of this book. Today the choice has been expanded to hundreds of new options offered by numerous and creative third parties worldwide. Interestingly, after much consideration, my final choice for this second edition has been to remain focused mainly on the Explorer16 demonstration board although the reader will be able to reproduces most/all examples and exercises on many other equivalent tools. This choice can be considered a testament to the success of the board in itself and the huge portfolio of