This book provides the technology fundaments and integration knowledge needed to interface a wide variety of sensors and actuators with the Arduino microcontroller. Readers will have at their fingertips a compendium covering the physical operation, in-circuit and program interfacing, sensor by sensor, for a range of physical quantities, as well as the actuators and control devices needed to operate on the physical world in response to an Arduino program. Alternative power schemes for the Arduino and sensor assembly (Direct, USB, battery, solar) are covered, and extensive references to hardware sources, spec sheets, and Open Hardware designs (where available or applicable) are included.