chandharrcs 0 Newbie Poster

Hi ..I am aa newbie to micro controller...I have a doubt about the usage of interfacing kit......Why cant we connect a keypad directly to the input port of microcontroller(for ex. 8051)..and the output pin of uC to the led matrix ???? What is the role of interfacing kit in between keypad-uC and uC-led matrix ?????

Can someone please explain ..?

Thanks in advance.