Seeed grove motion sensor control and actuator modules seeed studio 101020010 the grove ultrasonic range finder from seeed studio emits ultrasonic pulses and times the return signal to establish the distance between the sensor and a reflective object it can measure distances between 30mm and 4mseeed provide technical documentation example projects and software libraries on their product pages if you require this information please visit this products page seeed 101020010 grove ultrason