The document describes The IoT Testing Atlas, which is a method to systematically test all possible states of an Internet of Things (IoT) system. It does this by mapping out all potential states of each component in a circle diagram called an atlas. It then generates test cases by rotating the state of one component at a time while holding the others constant. This allows testing all combinations of states in a visual and comprehensive manner. The atlas approach scales well to complex IoT systems and provides a common framework to coordinate testing across teams.