VCC is the power supply for HC-SR04 Ultrasonic distance sensor which we connect the 5V pin on the Arduino. Trig (Trigger) pin is used to trigger the ultrasonic sound pulses. Echo pin produces a pulse when the reflected signal is received. The length of the pulse is proportional to the time it took for the transmitted signal to be detected. GND should be connected to the ground of Arduino. Hello friends, hope you all are fine and having good health. Graffiti fonts collection vol. 4.0 oz. In today's post I am gonna share an Ultrasonic Sensor Library for Proteus.Few days ago I have posted a tutorial on Arduino Library for Proteus which also has the Ultrasonic sensor in it but that's a quite basic library for Ultrasonic sensor, so here comes the new Ultrasonic Sensor Library for Proteus.