Universal Asynchronous Receiver Transmitter (UART) is a communication protocol which is mainly used for serial communication. In full duplex asynchronous UART mode, there is no need for clock synchronization between two devices. In this paper, we are analyzing and presenting the results of serially transmitting messages between two PIC16F877A Microcontrollers using UART protocol in full duplex mode. The simulation results show that, the full duplex bidirectional communication entirely depends upon the length of the characters transmitted and received. © 2006-2016 Asian Research Publishing Network (ARPN). All rights reserved.