使用4x3键盘配合Arduino

/*
 * Library taken from: https://playground.arduino.cc/Code/Keypad
 * This is the Arduino code for a 4x3 keypad.
 * Watch the video for details and demo: http://youtu.be/qIDzzG2LUtg
resources page: www.Robojax.com/RJT104
 * 
 * Modified by Ahmad Shamshiri for the Robojax Video channel: www.Robojax.com/RJT104
 * Date: July 11, 2018 at 19:56 in Ajax, Ontario, Canada
 * Permission granted to share this code, given that this
 * note is kept with the code.
 * Disclaimer: This code is "AS IS" and for educational purposes only.
 * This code has been downloaded from https://robojax.com
 * Watch video instructions for this code: 
 * 
 */
/* @file HelloKeypad.pde
|| @version 1.0
|| @author Alexander Brevig
|| @contact alexanderbrevig@gmail.com
||
|| @description
|| | Demonstrates the simplest use of the matrix Keypad library.
|| #
*/
#include <Keypad.h>

const byte ROWS = 4; //four rows
const byte COLS = 3; //three columns
char keys[ROWS][COLS] = {
  {'1','2','3'},
  {'4','5','6'},
  {'7','8','9'},
  {'*','0','#'}
};

byte rowPins[ROWS] = {2, 3, 4, 5}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {6,7,8}; //connect to the column pinouts of the keypad

Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

void setup(){
  // Robojax 4x3 keypad test
  Serial.begin(9600);
  Serial.println("Robojax 4x3 keypad");
}
  
void loop(){
  // Robojax 4x3 keypad test
  char key = keypad.getKey();
    // Just print the pressed key
   if (key){
    Serial.println(key);
  } 
   // This checks if 4 is pressed, then do something. Here we print the text, but you can control something.
  if (key =='4'){
    // If key matches what you are looking for
    Serial.println("Key 4 is pressed");
  } 

}