#include const byte ROWS = 4; // Four rows const byte COLS = 3; // Three columns // Define the Keymap char keys[ROWS][COLS] = { {'1','2','3'}, {'4','5','6'}, {'7','8','9'}, {'#','0','*'} }; // Connect keypad ROW0, ROW1, ROW2 and ROW3 to these Arduino pins. byte rowPins[ROWS] = { 9, 8, 7, 6 }; // Connect keypad COL0, COL1 and COL2 to these Arduino pins. byte colPins[COLS] = { 12, 11, 10 }; // Create the Keypad Keypad kpd = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS ); #define ledpin 13 void setup() { pinMode(ledpin,OUTPUT); digitalWrite(ledpin, HIGH); Serial.begin(9600); } void loop() { char key = kpd.getKey(); if(key) // Check for a valid key. { switch (key) { case '*': digitalWrite(ledpin, LOW); break; case '#': digitalWrite(ledpin, HIGH); break; default: Serial.println(key); } } }