Electronic engineer software development

I need the design for a 12 item vending machine using the MDB protocol to interface coin mech, card reader, bill acceptor. Should control prices and drive a display.  Save and send sales infromation. Would prefer to use  a Microchip PIC processor and C language.  Then teach me how it works so I can make software changes.  Youwill need to study the NAMA MDB protocol.