//Press 4 digits and display that Number.
//Ex: 1234,6754, 9870, etc

#include "register.h"
#include "functions.h"

#define ROWS 4
#define COLS 4

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

// Function to read the keypad
char read_keypad()
{
  uint8_t row, column;
  for (row = 0; row < ROWS; row++)
  {
    *outf = (1 << row); // Activate one row at a time
    for (column = 0; column < COLS; column++)
    {
      if ((*ink & (1 << column))) // Check each column in the active row
      {
        return keypad[row][column];
      }
    }
  }
  return 0;  // return zero for no press
}


void setup()
{
  *dirf = 0x0F; // Set first four pins of PORT F as o/p. KEYPAD row pins are connected to port f.
  *dirk = 0x00; // Set PORT K as i/p port. KEYPAD column pins are connected to port k.
  *dira = 0x0F; // Set first 4 pins of PORT A as o/p.
  *dirc = 0xFF; // Set PORT C as o/p.

  *outa = 0xFF; // turn off all segments initially

  char key;
  volatile long k = 0;
  int index, i = 0, j = 0;
  char arr[4] = {0};
  int segments[4] = {0x0E, 0x0D, 0x0B, 0x07}; // Array to store the segment selection values
  while (1)
  {
    if ((key = read_keypad()) != 0) {
      delay(200);  // use delay after reading a valid input
    }

    if (key >= '0' && key <= '9') // If a numeric key is pressed
    {
      arr[i] = key; // Store the key
      i = (i + 1) % 4; // Move to the next position, wrap around after 4
    }

    for (j = 0; j < 4; j++)
    {
      if (arr[j] != 0) // If a key has been pressed
      {
        index = arr[j] - '0';   // Convert the key to an index
        *outc = display(index); // Display the digit on the selected segment
        *outa = segments[j];    // Select the corresponding segment
        *outa = 0x0F;           // Turn off all segments
      }
    }
  }
}