مشروع 34: لوحة مفاتيح Keypad 4×4

#include <Keypad.h>
const byte ROWS = 4, COLS = 4;
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {2, 3, 4, 5};
byte colPins[COLS] = {6, 7, 8, 9};
Keypad kp = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

void setup() { Serial.begin(9600); }

void loop() {
  char k = kp.getKey();
  if (k) Serial.println(k);
}