2pcs Hc-sr04 Module

There are 4 out of the module: VCC , Trig, Echo, GND . So it's a very easy interface for controller to use it ranging. 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 Features - With IO trigger for at least 10us high signal. - Static current ( max ) : 2 mA ; Electrical level output : 5V high. - Detection distance: 2cm - 450cm ; High precision : 2mm. - Automatically sends eight 40kHz and identify whether there is a pulse signal back .