10-04-2017, 02:55 PM
For the interconnection with the microcontroller provides two lines namely TRIGGER and ECHO. The trip pin is an input pin, the MCU sends a high 10uS pulse on this line to tell the HC-SR04 to start taking a measurement.
![[Image: hcsr04_trigger_pulse.png]](http://digital-wizard.net/images/pages/hcsr04_trigger_pulse.png)
It can be understood in the following video: