#include <Keypad.h>
#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
#include <stdio.h>
#include <Stepper.h>

LiquidCrystal_I2C lcd(0x27,16,2);

const byte ROWS = 4;
const byte COLS = 4;

char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

byte rowPins[ROWS] = {28, 30, 32, 34};
byte colPins[COLS] = {42, 44, 46, 48}; 

Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

int relay = 13;
int counter = 0; 
int attempts = 0; 
int max_attempts = 3; 
String mymints;
int minutes = 0; 
String mysecs; 
int seconds = 0; 
long int total_seconds = 0; 
int secflag = 0; 
int timer_started_flag = 0; 
unsigned long previousMillis=0;
unsigned long int previoussecs = 0; 
unsigned long int currentsecs = 0; 
unsigned long currentMillis = 0;
int interval= 1 ;
int tsecs = 0; 

void setup(){
  lcd.init();                
  lcd.backlight();           
  pinMode(relay, OUTPUT);
  digitalWrite(relay, LOW);
  lcd.print("COUNTDOWN TIMER");
  delay(2000); 
  lcd.clear();
  lcd.print("ENTER MINUTES:");
}

void loop(){
 keypadfunction();
}
void keypadfunction(){ 
 char key = keypad.getKey();
  if (key){
   counter = counter + 1; 
   lcd.setCursor(counter, 1);
   lcd.print(key);
  }
   if (key == '1') {
    mymints = mymints + 1;   
  }
   if (key == '2'){
    mymints = mymints + 2;  
  }
   if (key == '3'){
    mymints = mymints + 3; 
  }
   if (key == '4'){
    mymints = mymints + 4;  
  }
   if (key == '5'){
    mymints = mymints + 5;
  }
   if (key == '6'){
    mymints = mymints + 6; 
  }
   if (key == '7'){
    mymints = mymints + 7; 
  }
   if (key == '8'){
    mymints = mymints + 8; 
  }
   if (key == '9'){
    mymints = mymints + 9;
  }
   if (key == '0'){
    mymints = mymints + 0; 
  }
   if (key == '#'){
    counter = 0;
    mymints = ""; 
    minutes = 0;  
    mysecs = ""; 
    seconds = 0; 
    secflag = 0;  
    lcd.clear(); 
    lcd.setCursor(0,0); 
    lcd.print("ENTER MINUTES:"); 
  }
    if (key == '*'){
     lcd.clear();     
     minutes = mymints.toInt();
     lcd.clear(); 
     lcd.print("  (SAVED MIN):  "); 
     lcd.setCursor(7,1); 
     lcd.print(minutes); 
     mymints = "";
      delay(2000); 
     lcd.clear();
     lcd.setCursor(0,0);
     lcd.print("ENTER SECOUNDS:");
     counter = 0; 
     secflag = 1; 
      while(secflag == 1){
       forSeconds();       
    }    
  }     
}
void forSeconds(){
 char key = keypad.getKey(); 
  if (key){
    counter = counter + 1; 
    lcd.setCursor(counter, 1);
    lcd.print(key);
  }
   if (key == '1'){
    mysecs = mysecs + 1;   
  }
   if (key == '2'){
    mysecs = mysecs + 2;  
  }
   if (key == '3'){
    mysecs = mysecs + 3; 
  }
   if (key == '4'){
    mysecs = mysecs + 4;  
  }
   if (key == '5'){
    mysecs = mysecs + 5;
  }
   if (key == '6'){
    mysecs = mysecs + 6; 
  }
   if (key == '7'){
    mysecs = mysecs + 7; 
  }
   if (key == '8'){
    mysecs = mysecs + 8; 
  }
   if (key == '9'){
    mysecs = mysecs + 9;
  }
   if (key == '0'){
    mysecs = mysecs + 0; 
  }
   if (key == '#'){
    counter = 0;
    mymints = ""; 
    minutes = 0;  
    mysecs = ""; 
    seconds = 0; 
    secflag = 0;  
    lcd.clear(); 
    lcd.setCursor(0,0); 
    lcd.print("ENTER MINUTES:"); 
  }
   if (key == '*'){
    lcd.clear();     
    seconds = mysecs.toInt();
    lcd.clear();
    lcd.setCursor(0,0); 
    lcd.print("  (SAVED SEC):  "); 
    lcd.setCursor(7,1); 
    lcd.print(seconds); 
    mysecs = "";
     delay(2000); 
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("Mins      Secs"); 
    lcd.setCursor(1,1); 
    lcd.print(minutes); 
    lcd.setCursor(10,1); 
    lcd.print(seconds); 
    total_seconds = (minutes * 60) + seconds ;
    counter = 0;
    secflag = 0; 
    timer_started_flag = 1;
    lcd.clear();
    lcd.print("TOTAL SEC:");
    lcd.setCursor(11,0);
    lcd.print( total_seconds );
    delay(3000); 
     while( timer_started_flag == 1){
      char key = keypad.getKey();
       if (key){
        counter = counter + 1; 
        lcd.setCursor(counter, 1);
        }
         if (key == '#'){
          counter = 0;
          mymints = ""; 
          minutes = 0;  
          mysecs = ""; 
          seconds = 0; 
          secflag = 0;  
          total_seconds = 0; 
          timer_started_flag = 0;
          lcd.clear(); 
          lcd.setCursor(0,0); 
          lcd.print("ENTER MINUTES:"); 
          }
          //lcd.clear(); 
            lcd.setCursor(0,0); 
            lcd.print("TOTAL SEC:");
            lcd.setCursor(11,0); 
            lcd.print( total_seconds );
            lcd.setCursor(0,1);
              if( total_seconds > 0){
               digitalWrite(relay, HIGH); 
               lcd.print("MOTOR IS RUNNING");
               }     
                if( total_seconds <= 0){
                 total_seconds = 0; 
                 digitalWrite(relay, LOW); 
                 lcd.print("MOTOR STOPPED"); 
                 }
                 currentMillis = millis();
                 currentsecs = currentMillis / 1000; 
                  if ((unsigned long)(currentsecs - previoussecs) >= interval) {
                   total_seconds = total_seconds - 1;
                   lcd.clear(); 
                   previoussecs = currentsecs;
                   }
             }
      }   
}