Aukru 3pcs HC-SR04 Ultrasonic Module Distance Sensor for Arduino UNO Mega R3 Mega2560 Duemilanove Nano Robot Xbee Zigbee

DC 5V HC-SR04 Ultrasonic Module Distance Sensor for Arduino UNO MEGA 2560 Nano Robot XBee ZigBee Features: Power supply :5V DC Quiescent current : <2mA Output signal: Electric frequency signal, high level 5V, low level 0V Effectual angle: <15 Ranging distance : 2cm-400cm Resolution : 0.3 cm There are 4 pins out of the module: VCC, trig(T), echo(R), GND, So it's a very easy interface for controller to use it ranging. The basic operation principle is below: 1.use IO port TRIG to trigger ranging. It needs 10 us high level signal at least 2.Module can send 8 pro 40 kz square wave automatically, and will test if there is any signal returned. 3.If there is signal returned, output one high level signal via IO port ECHO. The duration of the high level signal is the time from transmitter to receiving with the ultrasonic. The all process is: pull the Trig pin to high level for more than 10us impulse, the module start ranging; Finish ranging, If you find an object in front, Echo pin will be high level, and based on the different distance, it will take the different duration of high level. So we can calculated the distance easily: Distance = ((Duration of high level)*(Sonic :340m/s))/2 Package Included: 3 x HC-SR04 Distance Sensor Module