#include <avr/io.h>
#include <stdlib.h>
//----------- Global variable here ---#define
#define BAUDRATE 9600
#define VBAUDRATE (F_CPU/((unsigned long) BAUDRATE*16)-1)
#define BAUDH VBAUDRATE / 256
#define BAUDL VBAUDRATE % 256
// Global function here
void USARTInit(void);
volatile unsigned char USARTGetChar(void);
void USARTPutChar(unsigned char data);
void USARTPutStr(char *s);
void USARTBanner(void);
int main(void) {
//unsigned char tanda;
USARTInit();
USARTBanner();
while (1) {
USARTPutChar(USARTGetChar());
}
}
void USARTInit(void) {
// setup baudrate 
UBRR0H = BAUDH;
UBRR0L = BAUDL;
// Enable Receiver and Transmitter
UCSR0B = (1 << RXEN0) | (1 << TXEN0);
//Set frame format: 8data, 1stop bit
UCSR0C = (0 << USBS0) | (3 << UCSZ00);
}
volatile unsigned char USARTGetChar(void) {
//Wait for data to be received
while (!(UCSR0A & (1 << RXC0)))
;
return UDR0;
}
void USARTPutChar(unsigned char data) {
//Wait for empty transmit buffer
while (!(UCSR0A & (1 << UDRE0)))
;
UDR0 = data;
}
void USARTPutStr(char *s) {
char i = 0;
char c;
while ((c = *(s + (i++))) != 0)
USARTPutChar(c);
}
void USARTBanner(void) {
 USARTPutStr("\n\r");
USARTPutStr("**************************\n\r");
USARTPutStr("***** test usart    ******\n\r");
USARTPutStr("**************************\n\r");

}