AnUART,universal asynchronous receiver / transmitteris responsible for performing the main task in serial communications with computers.A secondUARTcan be used to receive the information. TheUARTperforms all the tasks, timing, parity checking, etc. needed for the communication. The only extra devices attached are line driver chips (MAX 232)capable of transforming theTTLlevel signals to line voltages(RS 232) and vice versa.
TheMAX232is an integrated circuit that converts signals from an RS-232 serial port to signals suitable for use inTTLcompatible digital logic circuits. The MAX232 is a dual driver/receiver and typically converts the RX, TX, CTS and RTS signals..
Thesample code for UARTcommunication is written in Code Vision AVR.The controller is programmed to transfer and receive the data at the baud rate of 9600.The controller used is ATMEGA 32. The datas transmitted by microcontroller can be viewed on hyper terminal or by usingX-CTU software.The datas can be transmitted to controller by assemble packets in terminal tab.