Abstract21.1 Contact: Buttons and Switches21.2 Light21.3 Angle of a Revolute Joint21.4 Position of a Prismatic Joint21.5 Acceleration and Angular Velocity: Gyros, Accelerometers, and IMUs21.6 Magnetic Field Sensing: Hall Effect Sensors21.7 Distance21.8 Force21.9 Temperature21.10 Current21.11 GPS21.12 Exercises