These sensors are very easy to use. First, connect the VCC and GND pins to the Arduino’s +5V and GND pins. Next, connect the Trigger and Echo pins to two digital pins on the Arduino, perhaps pins 2 and 3 for example.

Setting the Trigger Pin to HIGH for 10 microseconds will activate a measurement reading and then the pulseIn() function can be called on the Echo Pin to determine the distance. The length of the incoming pulse is proportional to the distance measured.