//R ปรับค่าได้

#include <LiquidCrystal_I2C.h>     //ต้องมี
LiquidCrystal_I2C lcd(0x27, 16, 2 ); //ต้องมี


void setup() {
  pinMode(2, INPUT);
  pinMode(3, OUTPUT);
  pinMode(13, OUTPUT);
  pinMode(4, INPUT_PULLUP);

  lcd.init();  //ต้องมี
  lcd.backlight(); //ต้องมี

}///////////////////////////


void loop() {
   digitalWrite(3, HIGH);
    delayMicroseconds(10);
    digitalWrite(3, LOW);
    int d = pulseIn(2, HIGH);
    lcd.setCursor(0, 0);
    lcd.print(d);
    int cm = d / 58;
    lcd.setCursor(0, 1);
     lcd.print(cm);
     if (cm <= 100 || cm >= 300) {
     digitalWrite(13, HIGH);
     } else {
     digitalWrite(13, LOW);
     }
     delay(500);
     lcd.clear();
     lcd.setCursor(10,0);    
  int sw = digitalRead(4);
  lcd.print(sw);
  if (sw == 0) {
    press();
  }
} /////////////////////////
void press() {
  digitalWrite(3, HIGH);
  delayMicroseconds(10);
  digitalWrite(3, LOW);
  int d = pulseIn(2, HIGH);
  int cm = d / 58;
  lcd.setCursor(13, 0);
  lcd.print(cm);
  delay(500);
  lcd.clear();
}