Abstract: In recent years, multiprocessor designs have converged towards uni?ed hardware architecture despite supporting different communication abstractions. Some recent designs have employed a programmable controller to manage system communication. The Master/Slave pattern is most commonly used when responding to user interface controls while displaying data simultaneously. Master/slave is model of communication where one device or process has unidirectional control over one or more other devices. In some systems a master is elected from a group of eligible devices, with the other devices acting in the role of slaves. We have developed a Master Slave Communication using three microcontroller AT89S52 which communicates through RS 232 serial bus. There are three units; first unit is a Master controller Circuit which controls different parameters; second unit is a Sensing unit which acts as a slave and third unit is another slave which is a display system.

Keywords: AT89S52, Master Controller Circuit, Salve circuit , RS-232 protocol.