Gravity Series DFRobot Gravity Series is ideal for applications like smart homes, robots, industrial manufacturing, and urban environmental monitoring. The Gravity series is essential for project prototypes, start-ups, and student productions. Gravity has a variety of professional and commonly used modules, with a wealth of imagination. These modules include pH water quality sensors for professional rivers, industrial wastewater testing professional applications, and infrared human body sensors, flame, ultrasonic, and other applications for all kinds of basic applications. Heart rate, UV, motion sensors, and other sensors can help open the possibility of wearable items.