UartTest.c

/*
 * UartTest.c
 *
 * Created: 30/4/2561 20:04:00
 * Author : peath
 */ 

#include <avr/io.h>

void UART_init() {
	// 9600 baud
	UBRR0 = 103;
	
	// 8n1 stop bit 1
	UCSR0A = 0; // U2X = 0
	UCSR0B = (1 << RXEN0) | (1 << TXEN0) | (0 << UCSZ02);
	UCSR0C = (0 << UMSEL01) | (0 << UMSEL00) | (0 << UPM01) | (0 << UPM00) |
			 (0 << USBS0) | (0 << UCSZ02) | (1 << UCSZ01) | (1 << UCSZ00);
}

char UART_read() {
	while ( ! (UCSR0A & (1 << RXC0)) );
	
	return UDR0;
}

void UART_write(char c) {
	while (! (UCSR0A & (1 << UDRE0)) );
	
	UDR0 = c;
}

int main(void)
{
	char c;
	int i;
	
	char youSaid[] = "You said: ";
	
    UART_init();
		
    while (1) 
    {
		c = UART_read();
		for (i = 0; youSaid[i] != '\0'; i++)
			UART_write(youSaid[i]);

		UART_write(c);
		UART_write('\r');
		UART_write('\n');
    }
}