#include<LiquidCrystal_I2C.h>
#include<Servo.h>
LiquidCrystal_I2C   lcd(0x27,16,2);
Servo  myservo;
int threshold=20;
int full=60;
int trigger=4;
int echo=3;
int ledhigh=5;
int ledlow=6;
int ledmiddle=7;
void setup() {
  myservo.attach(2);
  pinMode(ledhigh,OUTPUT);
  pinMode(ledmiddle,OUTPUT);
  pinMode(ledhigh,OUTPUT);
  pinMode(trigger,OUTPUT);
  pinMode(echo,INPUT);
}

void loop() {
   digitalWrite(trigger,LOW); 
   delay(5);
  digitalWrite(trigger,HIGH);
  delay(10);
  digitalWrite(trigger,LOW);
  int b=pulseIn(echo,HIGH);
  int level=b*0.034/2;
  int c=map(level,2,400,0,62);
  if(c>threshold){
    lcd.print("low");
    digitalWrite(ledlow,HIGH);
    myservo.write(90);
  }

}