Keypad compiling problem

Projects Programming
1

Hi,

I have a problem compiling the keypad example code. I'm getting the following error messages:

Keypad_zelf.cpp.o: In function __static_initialization_and_destruction_0': Keypad_zelf.cpp:22: undefined reference to Keypad::Keypad(char*, unsigned char*, unsigned char*, unsigned char, unsigned char)'
Keypad_zelf.cpp.o: In function loop': Keypad_zelf.cpp:35: undefined reference to Keypad::getKey()'

This is the code I use:

#include "Keypad.h"

const byte ROWS = 4; // Four rows
const byte COLS = 4; // Three columns

char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'#','0','*','D'}
};

// Connect keypad ROW0, ROW1, ROW2 and ROW3 to these Arduino pins.
byte rowPins[ROWS] = { 5, 4, 3, 2 };
// Connect keypad COL0, COL1 and COL2 to these Arduino pins.
byte colPins[COLS] = { 9, 8, 7, 6 }; 

// Create the Keypad
Keypad kpd = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

#define ledpin 13

void setup()
{
  digitalWrite(ledpin, HIGH);
  Serial.begin(9600);
}


void loop()
{
    char key = kpd.getKey();
  if(key)  // same as if(key != NO_KEY)
  {
    switch (key)
    {
      case '*':
        digitalWrite(ledpin, LOW);
        break;
      case '#':
        digitalWrite(ledpin, HIGH);
        break;
      default:
        Serial.println(key);
    }
  }
}

I hope some one can tell me what the problem is.

2

Looks like it is not linking with the Keyboard library. Have you got it installed? I think the library folder goes in a "libraries" folder in the Arduino folder where your sketches are kept.

3

Thank you. That was indeed the problem.