int Array_1[4][3] = {{1,2,3}, {7,8,9}, {6,5,4},{0,5,9}};   // This is int type 1D array of 4  rows and 3 columns (12 elements (4x3))
char keypad[4][4] = {{'1','2','3','A'},{'4','5','6','B'},{'7','8','9','C'},{'*','0','#','D'}};   // This is char type 1D array 4 rows and 5 columns (20 elements (4x5))
char keyPressed;
void setup()  
{
Serial.begin(115200);

for(int i = 2; i<6; i++)
{
  pinMode(i,OUTPUT);
}

for(int i = 6; i<10; i++)
{
  pinMode(i,INPUT);
}



}

void loop() 
{
  
  for(int i = 2; i<6; i++)
  {
    
    if(i>2)
    {
      digitalWrite(i-1, LOW);
      //Serial.print(i-1);
      //Serial.println("LOW");
    }

    if(i==2)
    {
      digitalWrite(5, LOW);
      //Serial.print(5);
      //Serial.println("LOW");
    }
    

    digitalWrite(i, HIGH);
    //Serial.print(i);
    //Serial.println("HIGH");

    //Serial.println("delay");
  int row;
  int clonmn =i-1; // column number from i(i is pin number)
  bool column_State; // low or high 0 or 1

    for(int j =6;j<10;j++ )
    {
      row = j-5; // row number = pin number - 5
      
      
   
      column_State= digitalRead(j);
      
      if(column_State==1)  // print row and columd only when row pin is high
            {
            Serial.print(clonmn);
            Serial.print(" ");
            Serial.print(row);
            Serial.print(":");
            Serial.print(column_State);
            Serial.print(" key : ");
            keyPressed = keypad[row-1][clonmn-1];
            Serial.println(keyPressed);

            }
      
      delay(20);
      
    }

    delay(20);

  }
}

void temp( int j) // j for temp
{
 int i; // for temp
//Serial.println(digitalRead(j));
      if(digitalRead(j))
      {
        Serial.print(i);
        Serial.print(" ");
        Serial.print(j);
        Serial.println();
      }

}










void test() // to save commands only
{
  
/*
  
  for(int i=0;i<4;i++)
  {
    for(int j=0;j<3;j++)
    {
      Serial.print(i) ;
      Serial.print(" ") ;
      Serial.print(j) ;
      Serial.print(" , ") ;
    }
      Serial.println() ;
  }


  for(int i=0;i<4;i++)
  {
    for(int j=0;j<3;j++)
    {
      Serial.print(Array_1[i][j]);
      Serial.print(" , ");
    }
      Serial.println() ;
  }

  */

 for(int i=0;i<4;i++)
  {
    for(int j=0;j<4;j++)
    {
      Serial.print(i) ;
      Serial.print(" ") ;
      Serial.print(j) ;
      Serial.print(" , ") ;
    }
      Serial.println() ;
    
  }
  
  
    Serial.println() ;
    Serial.println() ;



  for(int i=0;i<4;i++)
  {
    for(int j=0;j<4;j++)
    {
      Serial.print(i) ;
      Serial.print(" ") ;
      Serial.print(j) ;
      Serial.print(" : ") ;
      Serial.print(keypad[i][j]);
      Serial.print(" , ");
    }
      Serial.println() ;
  }

}