Serial Port Communication(RS232) is the way for the microcontroller to communicate with the outer world. Using Serial Port microcontroller can communicate with other microcontroller or PC. Serial communication is also helpful in debugging the microcontroller program. Some microcontrollers have built-in hardware called USART (universal synchronous asynchronous receiver-transmitter) to implement a serial communication interface. The Serial port configuration include, Baud Rate, Data Bits, Parity, and Stop Bit.