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

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

long duration, inches;
int set_val, percentage;
bool state, pump;
int buttonPin = 13;

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

  pinMode(8, OUTPUT);
  pinMode(9, INPUT);
  pinMode(10, INPUT_PULLUP);
  pinMode(11, INPUT_PULLUP);
  pinMode(12, OUTPUT);
  pinMode(buttonPin, INPUT);

  myservo.attach(10);
}

void loop() {
  digitalWrite(3, 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;

    set_val = EEPROM.read(0);
  if (set_val > 150) set_val = 150;


  lcd.setCursor(12, 0);
  if (percentage < 0) percentage = 0;
  lcd.print(percentage);
  lcd.print("%   ");

  // Water level pumping
  if (percentage < 30 && digitalRead(11)) {
    pump = 1;
  } else if (percentage > 99) {
    pump = 0;
  }

  // Pump on/off
  digitalWrite(12, !pump);
  lcd.setCursor(5, 1);
  lcd.print(pump ? "ON " : "OFF");

  // Slide switch
  lcd.setCursor(9, 1);
  lcd.print(digitalRead(11) ? "AUTO   " : "MANUAL");

  // Manual mode control using the push button
  if (!state && !digitalRead(11) && digitalRead(buttonPin)) {
    state = 1;
    set_val = inches;
    EEPROM.write(0, set_val);
    delay(10);
  }

  // Reset state when in AUTO mode
  if (state && digitalRead(11)) {
    state = 0;
  }

  // SERVO
  myservo.write(pump ? 0 : 180);

  delay(500);
}

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