Touchless Hand Sanitizer using HC SR04

 
#include <Servo.h>

const int trigPin = 7; // Trigger Pin of Ultrasonic Sensor
const int echoPin = 6; // Echo Pin of Ultrasonic Sensor
Servo Myservo;


void setup() 
{
Serial.begin(9600); // Starting Serial Terminal

Myservo.attach(5);  // Signal Pin of Servo      
                                       
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
Serial.print("  Distance    ");
Serial.print("  Measurement  ");
delay(1000);
delay(1000);
Serial.print("Made By :");

Serial.print(" OverAll Technical Gyan");
delay(2000);

}

void loop()
{
  long duration, cm;
  pinMode(trigPin, OUTPUT);
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  pinMode(echoPin, INPUT);
  duration = pulseIn(echoPin, HIGH);
  cm = microsecondsToCentimeters(duration);
  

Serial.print("Distance:");
  Serial.print(cm);
  Serial.print("cm");
  delay(100);
  
    if(cm >= 20){
Myservo.write(0);
}
else {
Myservo.write(90);


}

  Serial.println();
delay(100);

}


long microsecondsToCentimeters(long microseconds)
{
   return microseconds / 29 / 2;
}