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

LiquidCrystal_I2C lcd(0x27, 16, 2);

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

char keys [ROWS] [COLS] = { // Characters of the Keypad
  {'1', '2', '3', '+'},
  {'4', '5', '6', '-'},
  {'7', '8', '9', '*'},
  {'C', '0', '=', '/'}
};
byte rowPins[ROWS]={6, 7, 8, 9};
byte colPins[COLS]={5, 4, 3, 2};

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


boolean presentValue = false;
boolean next = false;
boolean final = false;
String num1, num2;
float answer ;
char op;


#define button_B    A0
#define button_D    A1
#define button_U    A2
#define button_E    A3

#define ONBOARD_LED 13

#define DEFAULT_DELAY 300

char buttonPressed = '0';

byte menuLevel = 0;     // Level 0: no menu display, display anything you like
                        // Level 1: display main menu
                        // Level 2: display sub menu

byte menu = 1;
byte sub = 1;

unsigned long relay_val_1 = 0;
unsigned long relay_val_2 = 0;
unsigned long relay_val_3 = 0;

bool LED_STATE = false;

bool currState_B = HIGH;
bool currState_D = HIGH;
bool currState_U = HIGH;
bool currState_E = HIGH;
          
bool prevState_B = HIGH; 
bool prevState_D = HIGH; 
bool prevState_U = HIGH; 
bool prevState_E = HIGH; 

unsigned long prevTime_B = 0;
unsigned long prevTime_D = 0;
unsigned long prevTime_U = 0;
unsigned long prevTime_E = 0;

unsigned long waitTime_B = 50;
unsigned long waitTime_D = 50;
unsigned long waitTime_U = 50;
unsigned long waitTime_E = 50;

const int button1   = A3;                   // button1 pin number
const int button2   = A1;                   // button1 pin number
const int button3   = A2;                   // button1 pin number
const int alarm_pin = 10;                   // Alarms pin number
 
void setup() {
  lcd.begin(16,2);
  lcd.init();

  Serial.begin(9600);

  pinMode(button_B, INPUT_PULLUP);
  pinMode(button_D, INPUT_PULLUP);
  pinMode(button_U, INPUT_PULLUP);
  pinMode(button_E, INPUT_PULLUP);

  pinMode(A4,INPUT);

  pinMode(A3, INPUT_PULLUP);
  pinMode(A1, INPUT_PULLUP);
  pinMode(A2, INPUT_PULLUP);
  pinMode(10, OUTPUT);
  digitalWrite(alarm_pin, LOW);
  // set up the LCD's number of columns and rows
  lcd.begin(16,2);
  Wire.begin();                                 // Join i2c bus
  attachInterrupt(digitalPinToInterrupt(2), Alarm, FALLING);


  pinMode(ONBOARD_LED, OUTPUT);
  digitalWrite(ONBOARD_LED, LED_STATE);
  
  showHomeScreen();
}

bool alarm1_status, alarm2_status;
char Time[]     = "  :  :  ",
     calendar[] = "      /  /20  ",
     alarm1[]   = "A1:   :  :00", alarm2[]   = "A2:   :  :00",
     temperature[] = "T:   .   C";
byte  i, second, minute, hour, day, date, month, year,
      alarm1_minute, alarm1_hour, alarm2_minute, alarm2_hour,
      status_reg;
 
void Alarm(){
  digitalWrite(alarm_pin, HIGH);
}
void DS3231_read(){                             // Function to read time & calendar data
  Wire.beginTransmission(0x68);                 // Start I2C protocol with DS3231 address
  Wire.write(0);                                // Send register address
  Wire.endTransmission(false);                  // I2C restart
  Wire.requestFrom(0x68, 7);                    // Request 7 bytes from DS3231 and release I2C bus at end of reading
  second = Wire.read();                         // Read seconds from register 0
  minute = Wire.read();                         // Read minuts from register 1
  hour   = Wire.read();                         // Read hour from register 2
  day    = Wire.read();                         // Read day from register 3
  date   = Wire.read();                         // Read date from register 4
  month  = Wire.read();                         // Read month from register 5
  year   = Wire.read();                         // Read year from register 6
}
void alarms_read_display(){                     // Function to read and display alarm1, alarm2 and temperature data
  byte control_reg, temperature_lsb;
  char temperature_msb;
  Wire.beginTransmission(0x68);                 // Start I2C protocol with DS3231 address
  Wire.write(0x08);                             // Send register address
  Wire.endTransmission(false);                  // I2C restart
  Wire.requestFrom(0x68, 11);                   // Request 11 bytes from DS3231 and release I2C bus at end of reading
  alarm1_minute = Wire.read();                  // Read alarm1 minutes
  alarm1_hour   = Wire.read();                  // Read alarm1 hours
  Wire.read();                                  // Skip alarm1 day/date register
  alarm2_minute = Wire.read();                  // Read alarm2 minutes
  alarm2_hour   = Wire.read();                  // Read alarm2 hours
  Wire.read();                                  // Skip alarm2 day/date register
  control_reg = Wire.read();                    // Read the DS3231 control register
  status_reg  = Wire.read();                    // Read the DS3231 status register
  Wire.read();                                  // Skip aging offset register
  temperature_msb = Wire.read();                // Read temperature MSB
  temperature_lsb = Wire.read();                // Read temperature LSB
    // Convert BCD to decimal
  alarm1_minute = (alarm1_minute >> 4) * 10 + (alarm1_minute & 0x0F);
  alarm1_hour   = (alarm1_hour   >> 4) * 10 + (alarm1_hour & 0x0F);
  alarm2_minute = (alarm2_minute >> 4) * 10 + (alarm2_minute & 0x0F);
  alarm2_hour   = (alarm2_hour   >> 4) * 10 + (alarm2_hour & 0x0F);
    // End conversion
  alarm1[8]     = alarm1_minute % 10  + 48;
  alarm1[7]     = alarm1_minute / 10  + 48;
  alarm1[5]     = alarm1_hour   % 10  + 48;
  alarm1[4]     = alarm1_hour   / 10  + 48;
  alarm2[8]     = alarm2_minute % 10  + 48;
  alarm2[7]     = alarm2_minute / 10  + 48;
  alarm2[5]     = alarm2_hour   % 10  + 48;
  alarm2[4]     = alarm2_hour   / 10  + 48;
  alarm1_status = bitRead(control_reg, 0);      // Read alarm1 interrupt enable bit (A1IE) from DS3231 control register
  alarm2_status = bitRead(control_reg, 1);      // Read alarm2 interrupt enable bit (A2IE) from DS3231 control register
  if(temperature_msb < 0){
    temperature_msb = abs(temperature_msb);
    temperature[2] = '-';
  }
  else
    temperature[2] = ' ';
  temperature_lsb >>= 6;
  temperature[4] = temperature_msb % 10  + 48;
  temperature[3] = temperature_msb / 10  + 48;
  if(temperature_lsb == 0 || temperature_lsb == 2){
    temperature[7] = '0';
    if(temperature_lsb == 0) temperature[6] = '0';
    else                     temperature[6] = '5';
  }
  if(temperature_lsb == 1 || temperature_lsb == 3){
    temperature[7] = '5';
    if(temperature_lsb == 1) temperature[6] = '2';
    else                     temperature[6] = '7';
  }
  temperature[8]  = 223;                        // Put the degree symbol
  lcd.setCursor(10, 0);
  lcd.print(temperature);                       // Display temperature
  lcd.setCursor(0, 2);
  lcd.print(alarm1);                            // Display alarm1
  lcd.setCursor(17, 2);
  if(alarm1_status)  lcd.print("ON ");          // If A1IE = 1 print 'ON'
  else               lcd.print("OFF");          // If A1IE = 0 print 'OFF'
  lcd.setCursor(0, 0);
  lcd.print(alarm2);                            // Display alarm2
  lcd.setCursor(17, 2);
  if(alarm2_status)  lcd.print("ON ");          // If A2IE = 1 print 'ON'
  else               lcd.print("OFF");          // If A2IE = 0 print 'OFF'
}
void calendar_display(){                        // Function to display calendar
  switch(day){
    case 1:  strcpy(calendar, "Sun   /  /20  "); break;
    case 2:  strcpy(calendar, "Mon   /  /20  "); break;
    case 3:  strcpy(calendar, "Tue   /  /20  "); break;
    case 4:  strcpy(calendar, "Wed   /  /20  "); break;
    case 5:  strcpy(calendar, "Thu   /  /20  "); break;
    case 6:  strcpy(calendar, "Fri   /  /20  "); break;
    case 7:  strcpy(calendar, "Sat   /  /20  "); break;
    default: strcpy(calendar, "Sat   /  /20  ");
  }
  calendar[13] = year  % 10 + 48;
  calendar[12] = year  / 10 + 48;
  calendar[8]  = month % 10 + 48;
  calendar[7]  = month / 10 + 48;
  calendar[5]  = date  % 10 + 48;
  calendar[4]  = date  / 10 + 48;
  lcd.setCursor(0, 1);
  lcd.print(calendar);                          // Display calendar
}
void DS3231_display(){
  // Convert BCD to decimal
  second = (second >> 4) * 10 + (second & 0x0F);
  minute = (minute >> 4) * 10 + (minute & 0x0F);
  hour = (hour >> 4) * 10 + (hour & 0x0F);
  date = (date >> 4) * 10 + (date & 0x0F);
  month = (month >> 4) * 10 + (month & 0x0F);
  year = (year >> 4) * 10 + (year & 0x0F);
  // End conversion
  Time[7]     = second % 10  + 48;
  Time[6]     = second / 10  + 48;
  Time[4]     = minute % 10  + 48;
  Time[3]     = minute / 10  + 48;
  Time[1]     = hour   % 10  + 48;
  Time[0]     = hour   / 10  + 48;
  calendar_display();                           // Call calendar display function
  lcd.setCursor(0, 0);
  lcd.print(Time);                              // Display time
}
void Blink(){
  byte j = 0;
  while(j < 10 && (digitalRead(button1) || i >= 5) && digitalRead(button2) && (digitalRead(button3) || i < 5)){
    j++;
    delay(25);
  }
}
byte edit(byte x, byte y, byte parameter){
  char text[3];
  while(!digitalRead(button1) || !digitalRead(button3));    // Wait until button B1 is released
  while(true){
    while(!digitalRead(button2)){                           // If button B2 is pressed
      parameter++;
      if(((i == 0) || (i == 5)) && parameter > 23)          // If hours > 23 ==> hours = 0
        parameter = 0;
      if(((i == 1) || (i == 6)) && parameter > 59)          // If minutes > 59 ==> minutes = 0
        parameter = 0;
      if(i == 2 && parameter > 31)                          // If date > 31 ==> date = 1
        parameter = 1;
      if(i == 3 && parameter > 12)                          // If month > 12 ==> month = 1
        parameter = 1;
      if(i == 4 && parameter > 99)                          // If year > 99 ==> year = 0
        parameter = 0;
      if(i == 7 && parameter > 1)                           // For alarms ON or OFF (1: alarm ON, 0: alarm OFF)
        parameter = 0;
      lcd.setCursor(x, y);
      if(i == 7){                                           // For alarms ON & OFF
        if(parameter == 1)  lcd.print("ON ");
        else                lcd.print("OFF");
      }
      else{
        sprintf(text,"%02u", parameter);
        lcd.print(text);
      }
      if(i >= 5){
        DS3231_read();                          // Read data from DS3231
        DS3231_display();                       // Display DS3231 time and calendar
      }
      delay(200);                               // Wait 200ms
    }
    lcd.setCursor(x, y);
    lcd.print("  ");                            // Print two spaces
    if(i == 7) lcd.print(" ");                  // Print space (for alarms ON & OFF)
    Blink();                                    // Call Blink function
    lcd.setCursor(x, y);
    if(i == 7){                                 // For alarms ON & OFF
      if(parameter == 1)  lcd.print("ON ");
      else                lcd.print("OFF");
    }
    else{
      sprintf(text,"%02u", parameter);
      lcd.print(text);
    }
    Blink();
    if(i >= 5){
      DS3231_read();
      DS3231_display();}
    if((!digitalRead(button1) && i < 5) || (!digitalRead(button3) && i >= 5)){
      i++;                                      // Increment 'i' for the next parameter
      return parameter;                         // Return parameter value and exit
    }          lcd.setCursor(0, 1);

  }
}
 
void buttonRTC() {
  if(!digitalRead(button1)){                    // If B1 button is pressed
      i = 0;
      hour   = edit(0, 0, hour);
      minute = edit(3, 0, minute);
      while(!digitalRead(button1));             // Wait until button B1 released
      while(true){
        while(!digitalRead(button2)){           // If button B2 button is pressed
          day++;                                // Increment day
          if(day > 7) day = 1;
          calendar_display();                   // Call display_calendar function
          lcd.print(calendar);                  // Display calendar
          delay(200);
        }
        lcd.setCursor(0, 1);
        lcd.print("   ");                       // Print 3 spaces
        Blink();
        lcd.setCursor(0, 1);
        lcd.print(calendar);                    // Print calendar
        Blink();                                // Call Blink function
        if(!digitalRead(button1))               // If button B1 is pressed
          break;
      }
      date = edit(4, 1, date);                  // Edit date
      month = edit(7, 1, month);                // Edit month
      year = edit(12, 1, year);                 // Edit year
      // Convert decimal to BCD
      minute = ((minute / 10) << 4) + (minute % 10);
      hour = ((hour / 10) << 4) + (hour % 10);
      date = ((date / 10) << 4) + (date % 10);
      month = ((month / 10) << 4) + (month % 10);
      year = ((year / 10) << 4) + (year % 10);
      // End conversion
      // Write time & calendar data to DS3231 RTC
      Wire.beginTransmission(0x68);             // Start I2C protocol with DS3231 address
      Wire.write(0);                            // Send register address
      Wire.write(0);                            // Reset sesonds and start oscillator
      Wire.write(minute);                       // Write minute
      Wire.write(hour);                         // Write hour
      Wire.write(day);                          // Write day
      Wire.write(date);                         // Write date
      Wire.write(month);                        // Write month
      Wire.write(year);                         // Write year
      Wire.endTransmission();                   // Stop transmission and release the I2C bus
      delay(200);
    }
    if(!digitalRead(button3)){                  // If B3 button is pressed
      while(!digitalRead(button3));             // Wait until button B3 released
      i = 5;
      alarm1_hour   = edit(4,  2, alarm1_hour);
      alarm1_minute = edit(7,  2, alarm1_minute);
      alarm1_status = edit(17, 2, alarm1_status);
      i = 5;
      alarm2_hour   = edit(4,  3, alarm2_hour);
      alarm2_minute = edit(7,  3, alarm2_minute);
      alarm2_status = edit(17, 3, alarm2_status);
      alarm1_minute = ((alarm1_minute / 10) << 4) + (alarm1_minute % 10);
      alarm1_hour   = ((alarm1_hour   / 10) << 4) + (alarm1_hour % 10);
      alarm2_minute = ((alarm2_minute / 10) << 4) + (alarm2_minute % 10);
      alarm2_hour   = ((alarm2_hour   / 10) << 4) + (alarm2_hour % 10);
      // Write alarms data to DS3231
      Wire.beginTransmission(0x68);               // Start I2C protocol with DS3231 address
      Wire.write(7);                              // Send register address (alarm1 seconds)
      Wire.write(0);                              // Write 0 to alarm1 seconds
      Wire.write(alarm1_minute);                  // Write alarm1 minutes value to DS3231
      Wire.write(alarm1_hour);                    // Write alarm1 hours value to DS3231
      Wire.write(0x80);                           // Alarm1 when hours, minutes, and seconds match
      Wire.write(alarm2_minute);                  // Write alarm2 minutes value to DS3231
      Wire.write(alarm2_hour);                    // Write alarm2 hours value to DS3231
      Wire.write(0x80);                           // Alarm2 when hours and minutes match
      Wire.write(4 | alarm1_status | (alarm2_status << 1));      // Write data to DS3231 control register (enable interrupt when alarm)
      Wire.write(0);                              // Clear alarm flag bits
      Wire.endTransmission();                     // Stop transmission and release the I2C bus
      delay(200);                                 // Wait 200ms
    }
    if(!digitalRead(button2) && digitalRead(alarm_pin)){         // When button B2 pressed with alarm (Reset and turn OFF the alarm)
      digitalWrite(alarm_pin, LOW);               // Turn OFF the alarm indicator
      Wire.beginTransmission(0x68);               // Start I2C protocol with DS3231 address
      Wire.write(0x0E);                           // Send register address (control register)
      // Write data to control register (Turn OFF the occurred alarm and keep the other as it is)
      Wire.write(4 | (!bitRead(status_reg, 0) & alarm1_status) | ((!bitRead(status_reg, 1) & alarm2_status) << 1));
      Wire.write(0);                              // Clear alarm flag bits
      Wire.endTransmission();                     // Stop transmission and release the I2C bus
    }
                               // Read time and calendar parameters from DS3231 RTC
                          // Read and display alarms parameters
                              // Display time &                             // Wait 50ms
}
void loop() {

  checkButton();
  callculator();
  
  // You can do other things here below

  
}

void callculator(){

  char key = myKeypad.getKey();

  if (key != NO_KEY && (key == '1' || key == '2' || key == '3' || key == '4' || key == '5' || key == '6' || key == '7' || key == '8' || key == '9' || key == '0'))
  {
    if (presentValue != true)
    {
      num1 = num1 + key;
      int numLength = num1.length();
      lcd.setCursor(0, 0); 
      lcd.print(num1);
    }
    else
    {
      num2 = num2 + key;
      int numLength = num2.length();
      int numLength1 = num1.length();
      lcd.setCursor(1 + numLength1, 0);
      lcd.print(num2);
      final = true;
    }
  }

  else if (presentValue == false && key != NO_KEY && (key == '/' || key == '*' || key == '-' || key == '+'))
  {
    if (presentValue == false)
    {
      int numLength = num1.length();
      presentValue = true;
      op = key;
      lcd.setCursor(0 + numLength, 0);
      lcd.print(op);
    }
  }

  else if (final == true && key != NO_KEY && key == '=') {
      
    if (op == '+') {
      answer = num1.toInt() + num2.toInt(); // Addition input
    }
    else if (op == '-') {
      answer = num1.toInt() - num2.toInt(); // Subtraction input
    }
    else if (op == '*') {
      answer = num1.toInt() * num2.toInt(); // Multiplication input
    }
    else if (op == '/') {
      answer = num1.toInt() / num2.toInt(); // Division input
    }
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print(num1);
    lcd.print(op);
    lcd.print(num2);
    lcd.setCursor(0,1);
    lcd.print("=");
    lcd.print(answer); // Printing answer on LCD screen
    presentValue = true;
    
  }
  else if (key != NO_KEY && key == 'C') { // Clearing input to clear everything on LCD screen
    lcd.clear();
    presentValue = false;
    final = false;
    num1 = "";
    num2 = "";
    answer = 0;
    op = ' ';
  }  
}

void checkButton() {
  // Button Debouncing
  bool currRead_B = digitalRead(button_B);
  bool currRead_D = digitalRead(button_D);
  bool currRead_U = digitalRead(button_U);
  bool currRead_E = digitalRead(button_E);
  if (currRead_B != prevState_B) {
    prevTime_B = millis();
  }
  if (currRead_D != prevState_D) {
    prevTime_D = millis();
  }
  if (currRead_U != prevState_U) {
    prevTime_U = millis();
  }
  if (currRead_E != prevState_E) {
    prevTime_E = millis();
  }
  if ((millis() - prevTime_B) > waitTime_B) {
    if (currRead_B != currState_B) {
      currState_B = currRead_B;
      if (currState_B == LOW) {
        buttonPressed = 'B';
      } 
    }
  } else buttonPressed = '0';
  if ((millis() - prevTime_D) > waitTime_D) {
    if (currRead_D != currState_D) {
      currState_D = currRead_D;
      if (currState_D == LOW) {
        buttonPressed = 'D';
      } 
    }
  } else buttonPressed = '0';
  if ((millis() - prevTime_U) > waitTime_U) {
    if (currRead_U != currState_U) {
      currState_U = currRead_U;
      if (currState_U == LOW) {
        buttonPressed = 'U';
      } else {
        //buttonPressed = '0';
      }
    }
  } else buttonPressed = '0';
  if ((millis() - prevTime_E) > waitTime_E) {
    if (currRead_E != currState_E) {
      currState_E = currRead_E;
      if (currState_E == LOW) {
        buttonPressed = 'E';
      } 
    }
  } else buttonPressed = '0';

  prevState_B = currRead_B;
  prevState_D = currRead_D;
  prevState_U = currRead_U;
  prevState_E = currRead_E;

  processButton(buttonPressed);
}

void processButton(char buttonPressed) {
  switch(menuLevel) {
    case 0: // Level 0
      switch ( buttonPressed ) {
        case 'E': // Enter
          menuLevel = 1;
          menu = 1;
          updateMenu();
          delay(DEFAULT_DELAY);
          break;
        case 'U': // Up
          break;
        case 'D': // Down
          break;
        case 'B': // Back
          break;
        default:
          break;
      }
      break;
    case 1: // Level 1, main menu
      switch ( buttonPressed ) {
        case 'E': // Enter
          updateSub();
          menuLevel = 2;  // go to sub menu
          updateSub();
          delay(DEFAULT_DELAY);
          break;
        case 'U': // Up
          menu++;
          updateMenu();
          delay(DEFAULT_DELAY);
          break;
        case 'D': // Down
          menu--;
          updateMenu();
          delay(DEFAULT_DELAY);
          break;
        case 'B': // Back
          menuLevel = 0;  // hide menu, go back to level 0
          showHomeScreen();
          delay(DEFAULT_DELAY);
          break;
        default:
          break;
      } 
      break;
    case 2: // Level 2, sub menu
      switch ( buttonPressed ) {
        case 'E': 
          menuLevel = 1;
          updateMenu();
          delay(DEFAULT_DELAY);
          break;
        case 'U': // U
          if (menu == 1) {
            if (relay_val_1 < 3600000) {  // 1 hour max
              relay_val_1 = relay_val_1 + 1;
            } else {
              relay_val_1 = 3600000;
            }
          } else if (menu == 2) {       
            if (relay_val_2 < 3600000) {  // 1 hour max
              relay_val_2 = relay_val_2 + 1;
            } else {
              relay_val_2 = 3600000;
            }
          } else if (menu == 3) {
            if (relay_val_3 < 3600000) {  // 1 hour max  
              relay_val_3 = relay_val_3 + 1;
            } else {
              relay_val_3 = 3600000;
            }
          }
          updateSub();
          delay(DEFAULT_DELAY);
          break;
        case 'D': // D
          if (menu == 1) {
            if (relay_val_1 == 0) {
              relay_val_1 = 0;
            } else {
              relay_val_1 = relay_val_1 - 1;
            }
          } else if (menu == 2) {
            if (relay_val_2 == 0) {
              relay_val_2 = 0;
            } else {
              relay_val_2 = relay_val_2 - 1;
            }
          } else if (menu == 3) {
            if (relay_val_3 == 0) {
              relay_val_3 = 0;
            } else {
              relay_val_3 = relay_val_3 - 1;
            }
          }
          updateSub();
          delay(DEFAULT_DELAY);
          break;
        case 'B': // L
          menuLevel = 1;  // go back to main menu
          updateMenu();
          delay(DEFAULT_DELAY);
          break;
        default:  
          break;
      } 
      break;
    case 3: // Level 3, sub menu of sub menu
    
      break;
    default:
      break;
  }
}

void updateMenu() {
  switch (menu) {
    case 0:
      menu = 1;
      break;
    case 1:
      lcd.clear();
      lcd.print(">JAM ");
      lcd.print(relay_val_1);
      lcd.setCursor(0, 1);
      lcd.print(" ALARM ");
      break;
    case 2:
      lcd.clear();
      lcd.print(" JAM ");
      lcd.setCursor(0, 1);
      lcd.print(">ALARM ");
      lcd.print(relay_val_2);
      break;
    case 3:
      lcd.clear();
      lcd.print(">KALKULATOR ");
      lcd.print(relay_val_3);
      lcd.setCursor(0, 1);
      lcd.print("             ");
      break;
    case 4:
      menu = 3;
      break;
  }
}

void updateSub() {
  switch (menu) {
    case 0:
      break;
    case 1:
      lcd.clear();
      void DS3231_read();
      DS3231_display();
      calendar_display();
      
      break;
    case 2:
      lcd.clear();
      alarms_read_display();
      buttonRTC();
      break;
    case 3:
      lcd.clear();
      callculator();
      break;
    case 4:
      menu = 3;
      break;
  }

}

void showHomeScreen() {
  lcd.clear();
  lcd.println("  TechToTinker  ");
  lcd.setCursor(0,1);
  lcd.println("  - R for menu  ");
}