DMX512 is a 3 wire interface protocol used in professional lighting. This app note by Microchip explains all the protocol details and how to implement it on any PIC microcontroller with a hardware UART peripheral. Only external part is a RS485 transceiver.
DMX512 transmitter sends 512 8bit data packets one after the other to 512 individual receivers connected on the same 3 wire bus. The receivers have preprogrammed addresses (one of 512) and wait for their packet to be sent in line. Both the transmitter and receivers use a 250Khz clock and are synced up using start and stop bits at the beginning and end of transmission.
This app note covers all the information you need to build a DMX512 transmitter or receiver. Source code is also provided, as well as all the UART register initialization to get you started on your DMX projects.