#include <EEPROM.h>
#include <LiquidCrystal.h>

LiquidCrystal lcd(2,3,4,5,6,7);

long duration, inches;
int set_val, percentage;
bool pump;

void setup() {
  lcd.begin(16, 2);
  lcd.print("WATER LEVEL:");
  lcd.setCursor(0, 1); 
  lcd.print("PUMP: OFF");

  pinMode(8, OUTPUT);  // Trigger pin for ultrasonic sensor
  pinMode(9, INPUT);   // Echo pin for ultrasonic sensor
  pinMode(10, OUTPUT); // Pump control pin
  pinMode(12, OUTPUT); // Buzzer pin
  
  set_val = EEPROM.read(0);
  if (set_val > 150) set_val = 150;
}

void loop() {
  digitalWrite(8, LOW);
  delayMicroseconds(2);
  digitalWrite(8, HIGH);
  delayMicroseconds(10);
  digitalWrite(8, LOW);
  
  duration = pulseIn(9, HIGH);
  inches = microsecondsToInches(duration);
  percentage = (set_val - inches) * 100 / set_val;
  
  lcd.setCursor(12, 0); 
  if (percentage < 0) percentage = 0;
  lcd.print(percentage);
  lcd.print("%   ");
  
  if (percentage < 30) {
    pump = true;
    tone(12, 1000); // Turn on buzzer with a frequency of 1000Hz
  } else if (percentage > 99) {
    pump = false;
    noTone(12); // Turn off buzzer
  }

  digitalWrite(10, pump); // Control the pump
  
  lcd.setCursor(7, 1); // Update the LCD cursor position
  if (pump) {
    lcd.print("ON ");
  } else {
    lcd.print("OFF");
  }
  
  delay(500);
}

long microsecondsToInches(long microseconds) {
  return microseconds / 74 / 2;
}