Wiring:
+5V (power supply positive)
Trig (control) RX
Echo (receive) TX
GND (power supply negative)

Basic Working Principle:
(1) Using IO port TRIG trigger measuring distance, high level signal for at least 10uS.
(2) Module automatically sends eight 40kHz square wave, automatically detects whether there is return signal.
(3) When there is return signal, through IO port ECHO output a high level, the duration of the high level is the time of ultrasonic wave from sending to returning.Test distance = (high level time * sound velocity (340m/S))/2;
This module is simple to use, a port sends a high level of more than 10uS, then wait for high level output at receive port. Timer was enabled once there is output, and read time when this port becomes low level, which is the time of this measurement. Use the time to calculate distance. Constantly cycle measurement can reach your mobile measuring values.
The ultrasonic timing diagram shows that you only need to provide a more than 10uS pulse trigger signal, the module inside will send eight 40kHz cycle level and detect return wave. Output echo signal once detect return signal. The pulse width of echo signal is proportional to the measured distance.Thus calculate the distance with interval between sending signal and receiving echo signal.
Formula:
uS/58= cm or uS/148= inches;
Or:
Distance = high level time * sound velocity(340m/S)/2;
Suggested test cycle is more than 60ms, in order to prevent effect of transmitting signal on echo signal.

Package Includes:
1 x Distance Measuring Module and Sensor