Tastiera.Pilotare uno o più led.

     /*
     author Alexander Brevig

     #include <Keypad.h>

     # define LED1 3
     # define LED2 4
   
     const byte RIGHE    = 4; 
     const byte COLONNE = 4; 
   
     char Tasti[RIGHE][COLONNE] =
       {{'1','2','3','C'},
        {'4','5','6','D'},
        {'7','8','9','E'},
        {'A','0','B','F'}};
      
     byte righe[RIGHE] = {8, 7, 6, 5}; 
     byte colonne[COLONNE] = {12, 11, 10, 9}; 

     // Creazione della tastiera
     Keypad cKeypad = Keypad( makeKeymap(Tasti),
                 righe, colonne, RIGHE, COLONNE); 

     void setup() 
      {pinMode     (LED1, OUTPUT);
       pinMode     (LED2,  OUTPUT);  
       digitalWrite(LED1,   HIGH);
       digitalWrite(LED2,   HIGH);
       Serial.begin(9600);       }
  
   void loop(){
        char Key = cKeypad.getKey();
  
         if (Key)
         {switch (Key)
                  {case 49: //valore ascii del numero 1
                   digitalWrite(LED1, HIGH);
                   break;
                   case 50: //valore ascii del numero 2
                   digitalWrite(LED2, HIGH);
                   break;
                   case 52: //valore ascii del numero 4
                   digitalWrite(LED1, LOW);
                   break;
                   case 53: //valore ascii del numero 5
                   digitalWrite(LED2, LOW);
                   break;     }
          Serial.println(Key);}
 }