#include <EEPROM.h>
#include <LiquidCrystal_I2C.h> // Library for LCD
unsigned long current, previous;
const long interval = 2000;
int button1 = 10;
int button2 = 11;
int led = 9;
const int clockPin = 3;
const int countPin = 4;
const int resetPin = 5;
const int rotation = 20;
const int address = 50;
long bit_inc = 0, counter;
String counter_s;
float RPM = 0.0;
int en1 = 0, en2 = 0, en3 = 0;
LiquidCrystal_I2C lcd(0x27, 20, 4); // I2C address 0x27, 16 column and 2 rows
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  lcd.init(); //initialize the lcd
  lcd.backlight(); //open the backlight 
  lcd.clear(); 
  lcd.clear(); 
  lcd.setCursor (0,1);
  lcd.print(" PH +91 9825440537");
  lcd.setCursor (0,0);
  lcd.print("C-TEX INDUSTRIES");
  lcd.setCursor(0,3);
  lcd.print("     Version  1.0");
  lcd.setCursor(0,2);
  lcd.print("   AHMEDABAD.INDIA");
  
  delay(2000);
  current = millis();
  previous = millis();
  pinMode(led, OUTPUT);
  pinMode(button1, INPUT_PULLUP);
  pinMode(button2, INPUT_PULLUP);
  pinMode(clockPin, INPUT);
  pinMode(countPin, INPUT);
  pinMode(resetPin, INPUT);
  // counter = EEPROM.read(address);
  counter_s = readStringFromEEPROM(address);
  counter = (counter_s.toInt()/10);
  // // for simulation only***********
  // if (counter == 255){
  //   counter = 0;
  //   EEPROM.write(address, counter);
  // }
  // //*******************************
  Serial.println("Program start:");
  lcd.clear(); 
  lcd.setCursor(0, 1);
  lcd.print("RPM: ");
  lcd.setCursor(5, 1);
  lcd.print(RPM);
  lcd.setCursor(0, 0);
  lcd.print("Total Knots:");
  lcd.setCursor(14, 0);
  lcd.print(counter);
}

void loop() {

  // put your main code here, to run repeatedly:
   int button1_state = digitalRead(button1);
  int button2_state = digitalRead(button2);
  if (button1_state == 0)
  {
    //LED ON
    digitalWrite(led, LOW);
  }
  if (button2_state == 0)
  {
    //LED OFF
    digitalWrite(led, HIGH);
  }
  current = millis();
  if (current - previous >= interval){
    previous = millis();
    // Serial.println("bit_inc for 2 sec: " + String(bit_inc));
    bit_inc = bit_inc *60;
    // Serial.println("bit_inc for 1 min: " + String(bit_inc));
    RPM = bit_inc/1;
    Serial.println("Counter: " + String(counter));
    Serial.println("RPM: " + String(RPM));
    lcd.setCursor(0, 1);
    lcd.print("RPM: ");
    lcd.setCursor(5, 1);
    lcd.print(RPM);
    bit_inc = 0;
  }
  
  if (digitalRead(clockPin) == 0 and en1 == 1){
    en1 = 0;
    bit_inc++;
  } 
  if (digitalRead(clockPin) == 1 and en1 == 0){
    en1 = 1;
  }

  if (digitalRead(countPin) == 0 and en2 == 0){
    en2 = 1;
  } 
  if (digitalRead(countPin) == 1 and en2 == 1){
    en2 = 0;
    counter++;
    if (counter >= 999999){
      counter = 999999;
    }
   
    writeStringToEEPROM(address, String(counter));
    lcd.setCursor(0, 0);
    lcd.print("Total Knots:");
    lcd.setCursor(14, 0);
    lcd.print(counter);
     lcd.setCursor (0,2);
  lcd.print("--------------------");
  lcd.setCursor (0,3);
  lcd.print("* C-TEX INDUSTRIES *");
  }
  if (digitalRead(resetPin) == 0 and en2 == 0){
    en3 = 1;
  } 
  if (digitalRead(resetPin) == 1 and en2 == 1){
    en3 = 0;
    counter = 0;
   
    writeStringToEEPROM(address, String(counter));
    lcd.setCursor(0, 0);
    lcd.print("Total Knots:");
    lcd.setCursor(14, 0);
    lcd.print(counter);
    lcd.setCursor(14, 0);
    lcd.print("     ");
   
  }
}

void writeStringToEEPROM(int addrOffset, const String &strToWrite)
{
  byte len = strToWrite.length();
  EEPROM.write(addrOffset, len);
  for (int i = 0; i < len; i++)
  {
    EEPROM.write(addrOffset + 1 + i, strToWrite[i]);
  }
}
String readStringFromEEPROM(int addrOffset)
{
  int newStrLen = EEPROM.read(addrOffset);
  char data[newStrLen + 1];
  for (int i = 0; i < newStrLen; i++)
  {
    data[i] = EEPROM.read(addrOffset + 1 + i);
  }
  data[newStrLen] = '\ 0'; // !!! NOTE !!! Remove the space between the slash "/" and "0" (I've added a space because otherwise there is a display bug)
  return String(data);
}