#include <avr/io.h>
#include <stdlib.h>
//----------- Global variable here ---
#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();

  while (1) {
    USARTPutChar('U');
  }
}

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);
}