Robotronics HC-SR04 Ultrasonic Sensor Distance Module for Arduino UNO MEGA2560 Nano Robot XBee ZigBee With Female To Female Jumper Wire FM Transmitter Electronic Hobby Kit

The module should be inserted in the circuit before been powered to avoid producing high level of misoperation; if producted, power it again. The module is not suggested to connect directly to electric, if connected electric, the GND terminal should be connected the module first, otherwise,it will affect the normal work of the module. When tested objects, the range of area is not less than 0.5 square meters and the plane requests as smooth as possible, otherwise ,it will affect the results of measuring.