#include <Keypad.h>
const byte ROWS = 4; 
const byte COLS = 4; 
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {A0,A1,A2,A3}; 
byte colPins[COLS] = {13,12,11,10}; 
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
const int segmentPins[] = {2, 3, 4, 5, 6, 7, 8}; 
const int commonPin = 9; 
void setup() {
  for (int i = 0; i < 7; i++) {
    pinMode(segmentPins[i], OUTPUT);
  }
  pinMode(commonPin, OUTPUT);
}
void loop() {
  char key = keypad.getKey();
  if (key) {
    
    displayNumber(key);
    delay(5);  
  }
}
void displayNumber(char number) {  
  byte segments[] = {
    B00111111, 
    B00000110, 
    B11011011, 
    B01001111, 
    B01100110, 
    B01101101, 
    B01111101, 
    B00000111, 
    B01111111, 
    B01101111  
  };
  int num = number - '0';
  digitalWrite(commonPin, HIGH); 
  for (int i = 0; i < 7; i++) {
    digitalWrite(segmentPins[i], bitRead(segments[num], i));
  }
  digitalWrite(commonPin, LOW);
  delay(1000);
  digitalWrite(commonPin, HIGH);
}