#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
float calibration_value = 21.34;
int set_val,percentage;
int phval = 0; 
unsigned long int avgval; 
int buffer_arr[10],temp;
int relay = 13;
const int trigPin = 9;
const int echoPin = 10;

float duration, distance;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(relay, OUTPUT);
  Serial.begin(9600);
  lcd.begin(16, 2);
  lcd.print("WATER LEVEL:");
  lcd.setCursor(0, 1); 
  lcd.print("PUMP:OFF MANUAL");
  delay(2000);
  lcd.clear();
}

void loop() {
  
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);
  distance = (duration*.0343)/2;
  Serial.print("Distance: ");
  Serial.println(distance);
  lcd.setCursor(0, 0);
  lcd.print("Level");
  lcd.setCursor(0, 1);
  lcd.print(distance);
  lcd.setCursor(6, 1);
  lcd.print("CM");
  lcd.setCursor(11,0);
  lcd.print("PUMP");

  delay(100);
    if(distance>295){
      do{
      digitalWrite(relay, HIGH);
      lcd.setCursor(11,1);
      lcd.print("ON");
      }while (distance<4);

      if(distance<4){
      digitalWrite(relay, LOW);
      lcd.setCursor(11,1);
      lcd.print("OFF");
      }
      }
    
    else if(distance<4){
      digitalWrite(relay, LOW);
      lcd.setCursor(11,1);
      lcd.print("OFF");
    }

}