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

int controlPin = 13;
int dirPin = 8;
int stepPin = 9;

char currentTimeValue[4];
int currentState = 1;
int timerSeconds = 0;
int lpcnt = 0;

LiquidCrystal_I2C lcd(0x27, 16, 2);

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

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

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

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

void setup(){
lcd.init();
lcd.backlight();

displayCodeEntryScreen();
pinMode(controlPin, OUTPUT);
digitalWrite(controlPin, LOW);
pinMode(stepPin, OUTPUT);
pinMode(dirPin, OUTPUT);
digitalWrite(stepPin, LOW);

currentTimeValue[0] = '0';
currentTimeValue[1] = '0';
currentTimeValue[2] = '0';
currentTimeValue[3] = '0';
showEnteredTime();
}

void loop(){
int l; 
char tempVal[3];

char key = keypad.getKey();

if (int(key) != 0 and currentState == 1){
  switch (key){
    case '*':
    relayStatus(false);
    currentTimeValue[0] = '0';
    currentTimeValue[1] = '0';
    currentTimeValue[2] = '0';
    currentTimeValue[3] = '0';
    showEnteredTime();
    currentState = 1;
    lpcnt = 0;
    timerSeconds = 0;
    break;
    
 case '#':
  tempVal[0] = currentTimeValue[0];
  tempVal[1] = currentTimeValue[1];
  tempVal[2] = 0;    
  
  timerSeconds = atol(tempVal) * 60;

  tempVal[0] = currentTimeValue[2];
  tempVal[1] = currentTimeValue[3];
  tempVal[2] = 0; 

timerSeconds = timerSeconds + atol(tempVal);
currentState = 2;
break;

default:
  currentTimeValue[0] = currentTimeValue[1];
  currentTimeValue[1] = currentTimeValue[2];
  currentTimeValue[2] = currentTimeValue[3];
  currentTimeValue[3] = key;
  showEnteredTime();
  break;
  }  
}

if (currentState == 2){
  if (int(key) != 0){
    if(key == '*'){
      relayStatus(false);
      displayCodeEntryScreen();
      currentTimeValue[0] = '0';
      currentTimeValue[1] = '0';
      currentTimeValue[2] = '0';
      currentTimeValue[3] = '0';
      showEnteredTime();
      currentState = 1;
      lpcnt = 0;
      timerSeconds = 0;
    }
  }
  else {
    if(lpcnt > 9){
      lpcnt = 0;
      --timerSeconds;
      showCountdown();

      if (timerSeconds <= 0){
        currentState = 1;
        relayStatus(false);
        displayCodeEntryScreen();
        showEnteredTime();
      } 
      else {
        relayStatus(true);
      }
    }
    ++lpcnt;
    delay(100);
  }
 }
}

void showEnteredTime(){
lcd.setCursor(5,1);
lcd.print(currentTimeValue[0]);
lcd.print(currentTimeValue[1]);
lcd.print(":");
lcd.print(currentTimeValue[2]);
lcd.print(currentTimeValue[3]); 
}

void relayStatus(bool status){
  if (status)
   digitalWrite(stepPin, HIGH);
  else
   digitalWrite(stepPin, LOW); 
}

void showCountdown(){
 char timest[6];

 lcd.setCursor(0,0);
 lcd.print(" COUNTING DOWN ");
 lcd.setCursor(2,1);
 lcd.print("**  ");
 sprintf(timest, "%d:%.2d" , (timerSeconds/60), (timerSeconds - ((timerSeconds/60)*60)));
 lcd.print(timest);
 lcd.print("  **"); 
}

void displayCodeEntryScreen(){
clearScreen();
lcd.setCursor(0,0);
lcd.print("Enter time:");
}

void clearScreen(){
  lcd.setCursor(0,0);
  lcd.print("                     ");
  lcd.setCursor(0,1);
  lcd.print("                     ");
}