hi Iam planning to use this example code to implement I2C keypad http://playground.arduino.cc/Main/I2CPortExpanderAndKeypads
this code has a header file i2ckeypad.h and a cpp file i2ckeypad.cpp . now if i write a program to use this library how do i include it in my code ? I know how to include the header files but how to link with the .cpp file ?
the example code given in the link above does not also link to this i2ckeypad.cpp file in any way so how does it find the routines from this library ?