#include<Keypad.h>

char keys[4][4]={
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

uint8_t led_pins[12]={11,10,9,8,7,6,5,4,3,2,28,27};
uint8_t row_pins[4]={26,22,21,20};
uint8_t col_pins[4]={19,18,17,16};

Keypad keypad=Keypad(makeKeymap(keys),row_pins,col_pins,4,4);

void setup() {
  for(int i=0;i<12;i++){
    pinMode(led_pins[i], OUTPUT);
    digitalWrite(led_pins[i], LOW);
  }
}

void loop() {
  char key=keypad.getKey();

  if(key!=NO_KEY){

    switch(key){

      case '1': digitalWrite(led_pins[0], HIGH);
                break;
      case '2': digitalWrite(led_pins[1], HIGH);
                break;
      case '3': digitalWrite(led_pins[2], HIGH);
                break;
      case '4': digitalWrite(led_pins[3], HIGH);
                break;
      case '5': digitalWrite(led_pins[4], HIGH);
                break;
      case '6': digitalWrite(led_pins[5], HIGH);
                break;
      case '7': digitalWrite(led_pins[6], HIGH);
                break;
      case '8': digitalWrite(led_pins[7], HIGH);
                break;
      case '9': 
                for(int i=0;i<8;i++){
                  digitalWrite(led_pins[i], HIGH);
                }
                break;
      case '0': 
                for(int i=0;i<8;i++){
                  digitalWrite(led_pins[i], LOW);
                }
                break;
      case 'A': digitalWrite(led_pins[8], HIGH);
                break;
      case 'B': digitalWrite(led_pins[9], HIGH);
                break;
      case 'C': digitalWrite(led_pins[10], HIGH);
                break;
      case 'D': digitalWrite(led_pins[11], HIGH);
                break;
      case '*': 
                for(int i=8;i<12;i++){
                  digitalWrite(led_pins[i], HIGH);
                }
                break;
      case '#': 
                for(int i=8;i<12;i++){
                  digitalWrite(led_pins[i], LOW);
                }
                break;

    }

  }

  delay(10);

}