#include <Keypad.h>

int led_1 = 13;
int led_2 = 12;
int led_3 = 11;
int led_4 = 10;

const byte ROWS = 4;
const byte COLS = 4;
char hexaKeys[ROWS][COLS] = {
  {' ',' ',' ',' '},
  {'1','2','3',' '},
  {'4','5','6',' '},
  {' ','0',' ',' '}
};
byte rowPins[ROWS] = {9, 8, 7, 6};
byte colPins[COLS] = {5, 4, 3, 2};

Keypad customKeypad = Keypad(makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS);

void setup(){
  Serial.begin(9600);
  pinMode(led_1, OUTPUT);
  pinMode(led_2, OUTPUT);
  pinMode(led_3, OUTPUT);
  pinMode(led_4, OUTPUT);
}

void loop(){
  char customKey = customKeypad.getKey();

  if (customKey){
    Serial.print(customKey);
    Serial.print(" - ");

    if(customKey == '1')
    {
      digitalWrite(led_1, HIGH);
      digitalWrite(led_2, LOW);
      digitalWrite(led_3, LOW);
      digitalWrite(led_4, LOW);
      Serial.println("0001");
      delay(800);
      digitalWrite(led_1, LOW);
    }

    else if(customKey == '2')
      {
      digitalWrite(led_1, LOW);
      digitalWrite(led_2, HIGH);
      digitalWrite(led_3, LOW);
      digitalWrite(led_4, LOW);
      Serial.println("0010");
      delay(800);
      digitalWrite(led_2, LOW);
      }

    else if(customKey == '3')
      {
      digitalWrite(led_1, HIGH);
      digitalWrite(led_2, HIGH);
      digitalWrite(led_3, LOW);
      digitalWrite(led_4, LOW);
      Serial.println("0011");
      delay(800);
      digitalWrite(led_1, LOW);
      digitalWrite(led_2, LOW);
      }

    else if(customKey == '4')
      {
      digitalWrite(led_1, LOW);
      digitalWrite(led_2, LOW);
      digitalWrite(led_3, HIGH);
      digitalWrite(led_4, LOW);
      Serial.println("0100");
      delay(800);
      digitalWrite(led_3, LOW);
      }

    else if(customKey == '5')
      {
      digitalWrite(led_1, HIGH);
      digitalWrite(led_2, LOW);
      digitalWrite(led_3, HIGH);
      digitalWrite(led_4, LOW);
      Serial.println("0101");
      delay(800);
      digitalWrite(led_1, LOW);
      digitalWrite(led_3, LOW);
      }

    else if(customKey == '6')
      {
      digitalWrite(led_1, LOW);
      digitalWrite(led_2, HIGH);
      digitalWrite(led_3, HIGH);
      digitalWrite(led_4, LOW);
      Serial.println("0110");
      delay(800);
      digitalWrite(led_2, LOW);
      digitalWrite(led_3, LOW);
      }

    else if(customKey == '7')
      {
      digitalWrite(led_1, HIGH);
      digitalWrite(led_2, HIGH);
      digitalWrite(led_3, HIGH);
      digitalWrite(led_4, LOW);
      Serial.println("0111");
      delay(800);
      digitalWrite(led_1, LOW);
      digitalWrite(led_2, LOW);
      digitalWrite(led_3, LOW);
      }

    else if(customKey == '8')
      {
      digitalWrite(led_1, LOW);
      digitalWrite(led_2, LOW);
      digitalWrite(led_3, LOW);
      digitalWrite(led_4, HIGH);
      Serial.println("1000");
      delay(800);
      digitalWrite(led_4, LOW);
      }

    else if(customKey == '9')
      {
      digitalWrite(led_1, HIGH);
      digitalWrite(led_2, LOW);
      digitalWrite(led_3, LOW);
      digitalWrite(led_4, HIGH);
      Serial.println("1001");
      delay(800);
      digitalWrite(led_1, LOW);
      digitalWrite(led_4, LOW);
      }

    else if(customKey == '0')
      {
      digitalWrite(led_1, LOW);
      digitalWrite(led_2, LOW);
      digitalWrite(led_3, LOW);
      digitalWrite(led_4, LOW);
      Serial.println("0000");
      delay(800);
      }
  }
}