Using HC-SR04 (Ultrasonic sensor) with arduino

HC-SR04 is an ultrasonic sensor which works on the principle of ultrasonic waves. Basically it creates a pulse depending on the distance from the sensor. It has two eyes like structure one of which transmits the waves and the other acts as receiver. The sensor has 4 pins VCC, TRIG, ECHO, GND. When the sensor is triggered by sending a pulse to TRIG pin, it sends a pulse through ECHO pin which can be measured.

1.      Parts needed: Arduino, wires, Ultrasonic Sensor (HC-SR04).

2.      Connections:

VCC pin to Arduino 5V

TRIG pin to Arduino pin 11

ECHO pin to Arduino pin 12

GND pin to Arduino GND

3.      Code:

void setup()   {   Serial.begin(9600); //Sensor TRIG pin to pin 11 pinMode(11, OUTPUT); //Sensor ECHO pin to pin 12 pinMode(12, INPUT);   } void loop()   {   int duration, distance; //to send trigger pin to pin 11 by activating it for 50 microseconds digitalWrite(11, HIGH); delayMicroseconds(50); digitalWrite(11, LOW); //pulseIn function measures the time for which the pulse is high duration = pulseIn(12, HIGH); //conversion of time to distance distance = duration * 0.034 / 2; //prints the distance on serial monitor Serial.print(distance); Serial.print(" cm"); delay(100);   }