//libraries
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
//#include "TimerOne.h"
#include <TimerOne.h>
#include <SPI.h>
#include <DHT.h>
#include "DHT.h"
#include <EEPROM.h>
// Display
// set the LCD address to 0x27 for a 20 chars and 4 line display
LiquidCrystal_I2C lcd(0x27, 20, 4);

#include "RTClib.h"
RTC_DS1307 rtc;
//int hour, minute, second =0;
int hour, minute, second;
int addr = 0;
void WellcomeScreen() {
  lcd.setCursor(2, 1);
  lcd.print("I am  M A Majeed");
  lcd.setCursor(5,2);
  lcd.print("This is my");
  lcd.setCursor(1, 3);
  String message = "Arduino Calculator";
  for (byte i = 0; i < message.length(); i++) {
    lcd.print(message[i]);
    delay(50);
  }
  delay(1000);
}

void MyTime() {
 
  DateTime now=rtc.now();
  hour=now.hour();
  minute = now.minute();
  second=now.second();

  String MyClk=String(hour)+":"+ String(minute)+":"+String(second);
  
  lcd.setCursor(12,0);
  if(hour<10)lcd.print("0");
  lcd.print(hour);
  lcd.print(":");
  if(minute<10)lcd.print("0");
  lcd.print(minute);
  lcd.print(":");
  if(second<10)lcd.print("0");
  lcd.print(second); 
}


#define DHTPIN 5     
#define DHTTYPE DHT22     // DHT 22  (AM2302), 
DHT dht(DHTPIN, DHTTYPE); // Initialize DHT sensor.

void myTemperature() {  

  // Reading temperature or humidity takes 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 

  // Read temperature as Celsius (the default)
  float t = dht.readTemperature();
 
  lcd.setCursor(0,0); lcd.print(t); lcd.print("c");

}

const uint8_t no_key = 0U;
// Keypad setup
const uint8_t ROWS = 5;
const uint8_t COLS = 5;
char keys_val[ROWS][COLS] = {

  {'F', 'C', 'S', '%', '/'},
  {'A', '7', '8', '9', '*'},
  {'B', '4', '5', '6', '-'},
  {'X', '1', '2', '3', '+'},
  {'Y', '0', '.', 'P', '='}
};


volatile uint8_t key_main_access;
volatile uint8_t key_state;
volatile uint8_t old_col;
volatile uint8_t new_col;
volatile uint8_t new_row;
volatile uint8_t main_read;
volatile uint8_t main_interrupted;
volatile uint8_t key1;
volatile uint8_t key2;

const int row_1 = 25;
const int row_2 = 27;
const int row_3 = 29;
const int row_4 = 31;
const int row_5 = 33;


const int col_1 = 37;
const int col_2 = 39;
const int col_3 = 41;
const int col_4 = 43;
const int col_5 = 45;

double myMemory = 0;

volatile uint32_t old_time, new_time, diff = 0U;
static const byte BUTTON_PIN = 3;

void setup()
{
  Serial.begin(115200);
  lcd.begin(20, 4);
  dht.begin();
  rtc.begin();
 
  WellcomeScreen();
 
    /* init all vars for keypad in default state */
  init_all_vars__key_c();

  /* 20ms timer interrupt */
  Timer1.initialize(20000);
  Timer1.attachInterrupt(isr_key_callback);

  /* all colums inout high */
  pinMode(col_1, INPUT_PULLUP);
  pinMode(col_2, INPUT_PULLUP);
  pinMode(col_3, INPUT_PULLUP);
  pinMode(col_4, INPUT_PULLUP);
  pinMode(col_5, INPUT_PULLUP);
  
  /* all rows output HIGH */
  pinMode(row_1, OUTPUT);
  pinMode(row_2, OUTPUT);
  pinMode(row_3, OUTPUT);
  pinMode(row_4, OUTPUT);
  pinMode(row_5, OUTPUT);

  digitalWrite(row_1, HIGH);
  digitalWrite(row_2, HIGH);
  digitalWrite(row_3, HIGH);
  digitalWrite(row_4, HIGH);
  digitalWrite(row_5, HIGH);
  
 
}

//void isr_key_callback()

void isr_key_callback()
{

  uint8_t check;

  if (0U == key_main_access)  /* if main is not accessing keypad variable, 
  will happen if main wants to reset keypad varaibles */
  {
    if (0U == key_state)   /* ground all rows & check for any col low */
    {
      digitalWrite(row_1, LOW); digitalWrite(row_2, LOW); digitalWrite(row_3, LOW); digitalWrite(row_4, LOW); digitalWrite(row_5, LOW);

      if (!digitalRead(col_1)) /* if found store the col & move to next state */
      {
        old_col = 1U;
        key_state = 1U;
      }
      else if (!digitalRead(col_2))
      {
        old_col = 2U;
        key_state = 1U;
      }
      else if (!digitalRead(col_3))
      {
        old_col = 3U;
        key_state = 1U;
      }
      else if (!digitalRead(col_4))
      {
        old_col = 4U;
        key_state = 1U;
      }
      else if (!digitalRead(col_5))
      {
        old_col = 5U;
        key_state = 1U;
      }
      else
      {
      }

    }
    else if (1U == key_state) /* ground one row at a time & check for col low  */
    {
      check = 0U;   /* assume row 1 is found to be low */
      digitalWrite(row_1, LOW); digitalWrite(row_2, HIGH); digitalWrite(row_3, HIGH); digitalWrite(row_4, HIGH); digitalWrite(row_5, HIGH);
     
      if (!digitalRead(col_1))  /* if found store the col & row */
      {
        new_col = 1U;
        new_row = 1U;
      }
      else if (!digitalRead(col_2))
      {
        new_col = 2U;
        new_row = 1U;
      }
      else if (!digitalRead(col_3))
      {
        new_col = 3U;
        new_row = 1U;
      }
      else if (!digitalRead(col_4))
      {
        new_col = 4U;
        new_row = 1U;
      }
      else if (!digitalRead(col_5))
      {
        new_col = 5U;
        new_row = 1U;
      }
      else
      {
        check = 1U;  /* initial assumption that this row found to be false, so now check next row */
      }

      if (1U == check)  /* repeat same as row 1 */
      {
        check = 0U;
        digitalWrite(row_1, HIGH); digitalWrite(row_2, LOW); digitalWrite(row_3, HIGH); digitalWrite(row_4, HIGH); digitalWrite(row_5, HIGH);
        
        if (!digitalRead(col_1))
        {
          new_col = 1U;
          new_row = 2U;
        }
        else if (!digitalRead(col_2))
        {
          new_col = 2U;
          new_row = 2U;
        }
        else if (!digitalRead(col_3))
        {
          new_col = 3U;
          new_row = 2U;
        }
        else if (!digitalRead(col_4))
        {
          new_col = 4U;
          new_row = 2U;
        }
        else if (!digitalRead(col_5))
        {
          new_col = 5U;
          new_row = 2U;
        }
        else
        {
          check = 1U;
        }
      }

      if (1U == check)   /* repeat same as row 1 */
      {
        check = 0U;
        digitalWrite(row_1, HIGH); digitalWrite(row_2, HIGH); digitalWrite(row_3, LOW); digitalWrite(row_4, HIGH); digitalWrite(row_5, HIGH);
        if (!digitalRead(col_1))
        {
          new_col = 1U;
          new_row = 3U;
        }
        
        else if (!digitalRead(col_2))
        {
          new_col = 2U;
          new_row = 3U;
        }
        else if (!digitalRead(col_3))
        {
          new_col = 3U;
          new_row = 3U;
        }
        else if (!digitalRead(col_4))
        {
          new_col = 4U;
          new_row = 3U;
        }
        else if (!digitalRead(col_5))
        {
          new_col = 5U;
          new_row = 3U;
        }

        else
        {
          check = 1U;
        }
      }

       if (1U == check)   /* repeat same as row 1 */
      {
        check = 0U;
        digitalWrite(row_1, HIGH); digitalWrite(row_2, HIGH); digitalWrite(row_3, HIGH); digitalWrite(row_4, LOW); digitalWrite(row_5, HIGH);
        
        if (!digitalRead(col_1))
        {
          new_col = 1U;
          new_row = 4U;
        }
        
        else if (!digitalRead(col_2))
        {
          new_col = 2U;
          new_row = 4U;
        }
        else if (!digitalRead(col_3))
        {
          new_col = 3U;
          new_row = 4U;
        }
        else if (!digitalRead(col_4))
        {
          new_col = 4U;
          new_row = 4U;
        }
        else if (!digitalRead(col_5))
        {
          new_col = 5U;
          new_row = 4U;
        }

        else
        {
          check = 1U;
        }
      }

      
       if (1U == check)   /* repeat same as row 1 */
      {
        check = 0U;
        digitalWrite(row_1, HIGH); digitalWrite(row_2, HIGH); digitalWrite(row_3, HIGH); digitalWrite(row_4, HIGH); digitalWrite(row_5, LOW);
        
        if (!digitalRead(col_1))
        {
          new_col = 1U;
          new_row = 5U;
        }
        
        else if (!digitalRead(col_2))
        {
          new_col = 2U;
          new_row = 5U;
        }
        else if (!digitalRead(col_3))
        {
          new_col = 3U;
          new_row = 5U;
        }
        else if (!digitalRead(col_4))
        {
          new_col = 4U;
          new_row = 5U;
        }
        else if (!digitalRead(col_5))
        {
          new_col = 5U;
          new_row = 5U;
        }

        else
        {
          check = 1U;
        }
      }

       if (1U == check)   /* repeat same as row 1 */
      {
        check = 0U;
        digitalWrite(row_1, HIGH); digitalWrite(row_2, HIGH); digitalWrite(row_3, HIGH); digitalWrite(row_4, HIGH); digitalWrite(row_5, HIGH);
        
        if (!digitalRead(col_1))
        {
          new_col = 1U;
          new_row = 6U;
        }
        
        else if (!digitalRead(col_2))
        {
          new_col = 2U;
          new_row = 6U;
        }
        else if (!digitalRead(col_3))
        {
          new_col = 3U;
          new_row = 6U;
        }
        else if (!digitalRead(col_4))
        {
          new_col = 4U;
          new_row = 6U;
        }
        else if (!digitalRead(col_5))
        {
          new_col = 5U;
          new_row = 6U;
        }

        else
        {
          check = 1U;
        }
      }


      if (0U == check)      /* a row low has been found */
      {
        if (new_col == old_col)  /* if new column & old colum has been equal */
        {
          if ((new_col >= 1) && (new_col <= 5) && (new_row >= 1) && (new_row <= 5)) /* if new col & new row are within array boundaries */
          {
            if (0U == main_read)          /* if main is not reading the key state */
            {
              key1 = keys_val[new_row - 1U][new_col - 1U];  /* store the key value */
            }
            else
            {
              key2 = keys_val[new_row - 1U][new_col - 1U]; /* mainline got interrupted */
              main_interrupted = 1U;
            }
            key_state = 2U;       /* key found successfully, now move to next state */
          }
          else
          {
            key_state = 0U;      /* if new col & new row are not within array boundaries, something wrong, move to default state */
          }
        }
        else  /* if new col & old col are not same, something wrong, move to default state */
        {
          key_state = 0U;
        }
      }
      else    /* if no row low has been found, something wrong,move to default state */
      {
        key_state = 0U;
      }

    }
    else if (2U == key_state)  /* wait for all keys to open again, by grounding all rows, & wait for col to be high */
    {
      digitalWrite(row_1, LOW); digitalWrite(row_2, LOW);  digitalWrite(row_3, LOW); digitalWrite(row_4, LOW); digitalWrite(row_5, LOW);
      if (digitalRead(col_1) && digitalRead(col_2) && digitalRead(col_3) && digitalRead(col_4)&& digitalRead(col_5))
      {
        key_state = 0U;    /* all col found high, move to default state */
      }
    }
    else
    {
    }

  }

}


void loop()
{

  uint8_t temp;
  
 // String num1;
  
  
  
  int i=0;
  while (1)
  {
    myTemperature();
    MyTime();
    temp = key_read();
   
    if (no_key != temp)
    {
     
     Serial.print("KEY: ");
     Serial.println((char)temp);

     myCalculator(temp);
      
      
     
        
    }
    
    
  }
}

uint8_t key_read(void)
{
  uint8_t temp;

  main_read = 1U;  /* set var for main line read & read the key value */
  temp = key1;
  key1 = no_key;
  main_read = 0U;

  if (1U == main_interrupted) /* if main line gets interupted, again read the key var */
  {
    temp = key2;
    key2 = no_key;
    main_interrupted = 0U;
  }

  return temp;

}

void clear_key_vars(void)
{
  key_main_access = 1U;    /* clear all previous key varaibles & start aagin  */

  key_state = 0U;
  old_col = 1U;
  new_col = 1U;
  new_row = 1U;
  main_read = 0U;
  main_interrupted = 0U;
  key1 = no_key;
  key2 = no_key;

  key_main_access = 0U;

}

void init_all_vars__key_c(void)
{
  key_main_access = 0U;   /* init ll vars to default state */
  key_state = 0U;
  old_col = 1U;
  new_col = 1U;
  new_row = 1U;
  main_read = 0U;
  main_interrupted = 0U;
  key1 = no_key;
  key2 = no_key;
}


uint8_t temp;

boolean presentValue = false; 
boolean next = false;
boolean next1 = false; 
boolean final = false; 
String num1, num2,num3; 
double answer; 
char Operator1=' ';
char Operator2=' ';
int numLength1 =0;
int numLength2 =0;
int DpState = LOW; 



void myCalculator(char temp){

if (((char)temp== '.' ||(char)temp== '1' ||(char)temp== '2' ||(char)temp== '3' ||(char)temp== '4' ||(char)temp== '5' ||(char)temp== '6' ||(char)temp== '7' ||(char)temp== '8' ||(char)temp== '9' ||(char)temp== '0' ))
{

  Serial.print("op2: ");
     Serial.println(Operator2);
     Serial.print("op1: ");
     Serial.println(Operator1);

  if (presentValue !=true)
  { 
    num1 += (char)temp;
 
    lcd.setCursor(0,2);   
    lcd.print(num1);
    Serial.print("num1: ");
    Serial.println(num1); 
    numLength1 =num1.length();
  }


  else if (next ==true)
   {
    num2 += (char)temp;
    
    lcd.setCursor(numLength1+1,2);   
    lcd.print(num2);
    Serial.print("num2: ");
    Serial.println(num2);
    numLength2 =num2.length();
    next1 = true;
   

   }
   else 
   {
    num3 += (char)temp;
     
    lcd.setCursor(numLength1+numLength2+2,2); 
    lcd.print(num3);
    Serial.print("num3: ");
    Serial.println(num3);
   

   }
}

//plus minus
else if ((char)temp== 'P' ) {

    num1= -1*(num1.toDouble());
    lcd.setCursor(0,2);
    lcd.print("                    ");
 
    lcd.setCursor(0,2);   
    //lcd.print("Sq:");
    lcd.print(num1);
    Serial.print("num1: ");
    Serial.println(num1); 
   numLength1 =num1.length();
    //numLength1 =num1.length();
    presentValue !=true;
    //myNumsEmpty();
 }
//square root
else if ((char)temp== 'S' ) {

    num1= sqrt(num1.toDouble());
    lcd.setCursor(0,2);
    lcd.print("                    ");
 
    lcd.setCursor(0,1);   
    lcd.print("Sqr:");
    lcd.print(num1);
    Serial.print("num1: ");
    Serial.println(num1); 
    //numLength1 =num1.length();
    presentValue !=true;
    myNumsEmpty();
 }

// Percentage
else if ((char)temp== '%' ) {

 num1= (num1.toDouble())*(num2.toDouble())/100;
 
    lcd.setCursor(0,2);
    lcd.print("                    ");
    lcd.setCursor(0,1);   
    lcd.print("P:");
    lcd.print(num1);
    Serial.print("num1: ");
    Serial.println(num1); 
    //numLength1 =num1.length();
    presentValue !=true;
    myNumsEmpty();

 }
// Memory M+
else if ((char)temp== 'Y' ) {

    myMemory+= (num1.toDouble());
    lcd.setCursor(0,2);
    lcd.print("                    ");
 
    lcd.setCursor(0,1);   
    lcd.print("M:");
    lcd.print(myMemory);
    Serial.print("myMemory: ");
    Serial.println(myMemory); 
    //numLength1 =num1.length();
    presentValue !=true;
    myNumsEmpty();
 }
// Memory M-
 else if ((char)temp== 'X' ) {

    myMemory-= (num1.toDouble());
    lcd.setCursor(0,2);
    lcd.print("                    ");
 
    lcd.setCursor(0,1);
    lcd.print("M:");   
    lcd.print(myMemory);
    Serial.print("myMemory: ");
    Serial.println(myMemory); 
    //numLength1 =num1.length();
    presentValue !=true;
    myNumsEmpty();
 }

// Memory Recall
 else if ((char)temp== 'B' ) {

   // myMemory-= (num1.toDouble());
    lcd.setCursor(0,1);
    lcd.print("                    ");
 
    lcd.setCursor(0,1);
    lcd.print("M:");   
    lcd.print(myMemory);
    Serial.print("myMemory: ");
    Serial.println(myMemory); 
    //numLength1 =num1.length();
    presentValue !=true;
    myNumsEmpty();
 }
// Memory Clear
else if ((char)temp== 'A' ) {

    myMemory=0;
    lcd.setCursor(0,2);
    lcd.print("                    ");
 
    lcd.setCursor(0,1);
    lcd.print("M:");   
    lcd.print(myMemory);
    Serial.print("myMemory: ");
    Serial.println(myMemory); 
    //numLength1 =num1.length();
    presentValue !=true;
    myNumsEmpty();
 }

else if (((char)temp== '/' ||(char)temp== '*' ||(char)temp== '-' ||(char)temp== '+' ))

{
  if (presentValue == false )
   {
    //if ((char)temp== '-' ||(char)temp== '+' ))
    presentValue = true;
    Operator1=(char)temp;
    lcd.setCursor(numLength1,2); 
    lcd.print(Operator1); 
    next= true;
    Serial.println(next);
   
   }

  else if (next1 == true && (char)temp!= '=')
   {
    
     next = false;
     Operator2=(char)temp;

     Serial.print("op2: ");
     Serial.println(Operator2);
     Serial.print("op1: ");
     Serial.println(Operator1);
     lcd.setCursor(numLength1+numLength2+1,2); 
     lcd.print(Operator2); 
     next1= false; 
   }

}

else if ((char)temp == '=')
{

     Serial.print("calop2: ");
     Serial.println(Operator2);
     Serial.print("calop1: ");
     Serial.println(Operator1);
 
 //calculation part for num1, num2
  if (Operator2 ==' ')
 {
   
  switch (Operator1) { 
      
        case '*':
          answer= num1.toDouble()* num2.toDouble();
          break;
     
        case '/':
          answer= num1.toDouble()/ num2.toDouble();
          break;
      
        case '+':
          answer= num1.toDouble()+ num2.toDouble();
          break;

        case '-':
          answer= num1.toDouble()- num2.toDouble();
          break;   

      }
 }	  
 
 else

//calculation part for num1,num2,num3
  switch (Operator1) {
      Serial.print("Operator2: ");
      Serial.println(Operator2); 
    
    case '*':
    {
      switch (Operator2) { 
      
        case '*':
          answer= num1.toDouble()* num2.toDouble()* num3.toDouble();
          break;
     
        case '/':
          answer= num1.toDouble()* num2.toDouble()/ num3.toDouble();
          break;
      
        case '+':
          answer= num1.toDouble()* num2.toDouble()+ num3.toDouble();
          break;

        case '-':
          answer= num1.toDouble()* num2.toDouble()- num3.toDouble();
          break;   

      }
    
    }
      break;

    case '/':
    { 
      switch (Operator2) { 
     
        case '*':
          answer= num1.toDouble()/ num2.toDouble()* num3.toDouble();
          break;
      
        case '/':
          answer= num1.toDouble()/ num2.toDouble()/ num3.toDouble();
          break;
        
        case '+':
          answer= num1.toDouble()/ num2.toDouble()+ num3.toDouble();
          break;

        case '-':
          answer= num1.toDouble()/ num2.toDouble()- num3.toDouble();
          break;   

      }
    }
    break;

    case '+': 
      switch (Operator2) { 
      
        case '*':
          answer= num1.toDouble()+ num2.toDouble()* num3.toDouble();
          break;
     
        case '/':
          answer= num1.toDouble()+ num2.toDouble()/ num3.toDouble();
          break;
      
        case '+':
          answer= num1.toDouble()+ num2.toDouble()+ num3.toDouble();
          break;

        case '-':
          answer= num1.toDouble()+ num2.toDouble()- num3.toDouble();
          break;   
      }
      break;

    case '-': 
     
     switch (Operator2) { 
      
        case '*':
          answer= num1.toDouble()- num2.toDouble()* num3.toDouble();
          break;
     
        case '/':
          answer= num1.toDouble()- num2.toDouble()/ num3.toDouble();
          break;
      
        case '+':
          answer= num1.toDouble()- num2.toDouble()+ num3.toDouble();
          break;

        case '-':
          answer= num1.toDouble()- num2.toDouble()- num3.toDouble();
          break;   

      }
      break;
  }  
  
  
 Serial.print("answer: ");
 Serial.println(answer);
 
  lcd.setCursor(0,3);
  lcd.print("=");
  lcd.print(answer);
 //lcd.noAutoscroll();

 
}

else if ((char)temp == 'C'){
  myScreenCleaner();
}

else if ((char)temp == 'F'){
  myOnOff();
}
  
/*
else if ((char)temp =='P') { 
    
  // Serial.print("answer:PPPP ");
    if ((char)temp== '+'){
        (char)temp== '-';
    }
    else  if ((char)temp== '-'){
        (char)temp== '+'; 
}

 // num1= -1*(num1.toDouble());
    answer=-1*(answer);
    lcd.setCursor(0,3);
    lcd.print("                    ");
 
    lcd.setCursor(0,3);
    lcd.print("=");
    lcd.print(answer);
    presentValue !=true;
  } 
*/

}  //my calculator ending



void myNumsEmpty(){

      presentValue = false;
      final = false;
      next = false;
      next1 = false;

      num1 = "";
      num2 = ""; 
      num3 = "";
      answer=0;
  
      Operator1 = ' ';
      Operator2 = ' ';  

    } 

 void myScreenCleaner(){

      lcd.setCursor(0,1);
      lcd.print("                    ");
      lcd.setCursor(0,2);
      lcd.print("                    ");
      lcd.setCursor(0,3);
      lcd.print("                    ");

      presentValue = false;
      final = false;
      next = false;
      next1 = false;

      num1 = "";
      num2 = ""; 
      num3 = "";
      answer=0;
  
      Operator1 = ' ';
      Operator2 = ' ';  

    } 


void myOnOff(){
// toggle state of dp
   DpState = !DpState;
    if(DpState==HIGH)
    {
      lcd.noDisplay(); // turn off the display
      //lcd.print("hello, world!");
      lcd.noCursor(); // turn off the cursor
      //lcd.clear(); 
    }
      
    else if(DpState==LOW)
    {
      lcd.display();   // turn on the display
     // lcd.cursor();
      lcd.clear();
     // lcd.home();  // move the cursor to the upper-left corner of the LCD
   
      presentValue = false;
      final = false;
      next = false;
      next1 = false;

      num1 = "";
      num2 = ""; 
      num3 = "";
      answer=0;
  
      Operator1 = ' ';
      Operator2 = ' ';  

    } 
}