EPLZON HC-SR04 Ultrasonic Module Distance Sensor fit for Arduino UNO MEGA Nano Robot XBee ZigBee HC-SR04 can measure the distance between the sensor and the object by the time from the sound wave of a specific frequency to the time it takes to hear the sound wave bounce. HC-SR04 is composed of ultrasonic transmitter, receiver and control circuit. Connection method: VCC/trig(T)/Echo(R)/GND (VCC provides 5V, GND is the ground wire. TRIG is the trigger control signal input, and ECHO is the echo signal output.) Working principle of ultrasonic sensor module Pull the Trig pin high for more than 10us pulses, and the module will start ranging. The module automatically sends 8 40KHz square waves to detect whether there is a signal return. After the ranging is completed, if there is an object in front of it, the Echo pin will be high, and the duration of the high level is different depending on the distance. So we can easily calculate the distance. Distance = ((high level duration) * (sound wave: 340m/s))/2. Distance L = 1/2 × T × C notes: ➤The module should be inserted into the circuit before power-on to avoid high-level misoperation; if it occurs, power-on again. ➤It is not recommended to connect the module directly. If you connect to the power, you need to connect the GND terminal of the module to the module first, otherwise it will affect the normal operation of the module. ➤When the object is measured, the area range is not less than 0.5 square meters, and the plane is required to be as flat as possible, otherwise it will affect the measurement result. Package Included: 5pcs x HC-SR04 ultrasonic measurement sensor module. 10pcs x female-male DuPont cable 10pcs x female-female DuPont cable