Chocolate Milk Machine (Circuit)

#include <Servo.h>
Servo servo_9;
#include <LiquidCrystal.h>
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

long readUltrasonicDistance(int triggerPin, int echoPin)
{
  pinMode(triggerPin, OUTPUT);  // Clear the trigger
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  pinMode(echoPin, INPUT);
  return pulseIn(echoPin, HIGH);
}

void setup()
{
  servo_9.attach(9, 500, 2500);
  
  lcd.begin(16,2);
  
  lcd.print("Insert Milk");

}

void loop()
{
  0.01723 * readUltrasonicDistance(7, 6);

  if (0.01723 * readUltrasonicDistance(7, 6) < 8){
    lcd.clear();
    lcd.print("Processing...");
    servo_9.write(180);
    delay(1000);
  }
  else{
    lcd.clear();
    lcd.print("Insert Milk");
    servo_9.write(0);
    delay(1000);
  }
}