Feature:
1.Main technical parameters:
Voltage: DC 5V
Static current: less than 2mA
Electrical level output: 5V high
Electrical level output: at the end of 0V
Induction angle: not more than 15 degrees
Detection distance: 2cm-450cm
High precision: 2mm
Wiring: VCC, trig (control side), echo (receiving end), GND
2.Module works:
using IO trigger distance, the high signal to at least 10us
module automatically sends eight 40khz square wave, automatically detects whether a signal return;
a signal back, through the IO output a high electrical level, high electrical level duration is: the ultrasound time from launch to return. Test distance = (time of the high electrical level * speed of sound (340M / S)) / 2;

Package Included:
5 x Ultrasonic Sensor Module HC-SR04 Distance Measuring Sensor For Arduino