This project is a RS-485 based bidirectional communications system using PIC18F4520 to communicate between several nodes. The project will consist of two separate circuits (per node) a) an RS-232 to 2-wire RS-485 converter and b) a 2-wire RS-485 peripheral transceiver.The converter will allow a PC serial port to be converted to and from electrical signal levels required for 2-wire RS-485 format. The RS-485 interface allows up to 32 standard load nodes on a shared data bus.[more]

This converter is intended to use with PC computer to communicate with ROV using 2 wires in half duplex mode. Send/receive mode is selected by RTS signal. The converter was designed to be as simple as possible, so it has no some features that can be found in commercial grade products.[more]