Simple AVR UART library

uart.cpp

#include "uart.h"
#include <avr/io.h>

unsigned int uart_calc_ubrr(unsigned long fosc, unsigned long baud)
{
	unsigned int ubrr;
	unsigned long div, rem;
	
	div = 16 * baud;
	rem = fosc / div;
	
	ubrr = (fosc / div) - 1;
	
	if(rem >= div / 2)
	{
		ubrr++;
	}
	
	return ubrr;
}

void uart_init(unsigned int ubrr)
{
	UBRRH = (unsigned char)(ubrr>>8);
	UBRRL = (unsigned char)ubrr;
	
	UCSRA = 0;
	UCSRB = (1<<RXEN) | (1<<TXEN);
	UCSRC = (1<<URSEL) | (1<<UCSZ0) | (1<<UCSZ1);
}

void uart_send_char(unsigned char c)
{
	while(!(UCSRA & (1<<UDRE)));
	UDR = c;
}

bool uart_available()
{
	return UCSRA & (1<<RXC);
}

unsigned char uart_get_char()
{
	while(!uart_available());
	return UDR;
}

void uart_send_string(unsigned char s[])
{
	for(int i=0; s[i]!=0; i++)
	{
		uart_send_char(s[i]);
	}
}

bool uart_get_string(unsigned char s[], unsigned char endc)
{
	uint8_t len;
	for(len=0; s[len]!=endc; len++);
	
	unsigned char c = uart_get_char();
	
	if(c != endc)
	{
		s[len] = c;
		s[len+1] = endc;
		
		return false;
	}
	
	return true;
}

uart.h

#ifndef UART_H_
#define UART_H_

unsigned int uart_calc_ubrr(unsigned long fosc, unsigned long baud = 9600);
void uart_init(unsigned int ubrr);
void uart_send_char(unsigned char c);
bool uart_available();
unsigned char uart_get_char();
void uart_send_string(unsigned char s[]);
bool uart_get_string(unsigned char s[], unsigned char endc = '\0');

#endif /* UART_H_ */