#ifndef SERIAL_H_

#define SERIAL_H_



#include <avr/io.h>

#include <avr/interrupt.h>



#define F_CPU 7372800UL



//Initialize USART

void usart_init(unsigned int baud);



//Check if a character has been received

uint8_t usart_rx_check(void);



//Get received character

unsigned char usart_getc(void);



//Send Character over USART

void usart_putc(unsigned char c);



#endif /* SERIAL_H_ */

#include "serial.h"



unsigned char rxbuf;

uint8_t rxflag = 0;



//USART receive interrupt routine

ISR(USART_RX_vect) {

    rxbuf = (unsigned char)UDR;	

	rxflag = 1;

}



//Initialize USART

void usart_init(unsigned int baud) {

	unsigned int ubrr;

	

	ubrr = (F_CPU / 16 / baud) - 1;

	

	//Set baud rate 

	UBRRH = (unsigned char)(ubrr>>8);

	UBRRL = (unsigned char)ubrr;



	// Enable receiver and transmitter 

	UCSRB = (1<<RXCIE)|(1<<RXEN)|(1<<TXEN);

	// Set frame format: 8data, 1stop bit 

	UCSRC = /*(1<<USBS)|*/(3<<UCSZ0);

}



//Check if a character has been received

uint8_t usart_rx_check(void) {

	return rxflag;

}



//Get received character

unsigned char usart_getc(void) {

	rxflag = 0;

	return rxbuf;

}



//Send Character over USART

void usart_putc(unsigned char c) {

	while (!(UCSRA & (1<<UDRE)) );		// wait for empty transmit Register

	UDR = c;							// Put data into buffer, sends the data

}