#include <avr/io.h>
#include <avr/interrupt.h>
#define F_CPU 8000000 // CPU speed - always define prior to including util/delay.h
#include <util/delay.h>
#define BAUD 9600
#define BRC ((F_CPU / BAUD) / 8) - 1
int main(void){
UBRR0H = 0x00; // set bit rate
UBRR0L = BRC;
UCSR0A = 0b00000010; // double bit rate enabled
UCSR0B = 0b00001000; // TxD enable
UCSR0C = 0b00000110; // asynchronous mode, 8N1 frame format
while(1){
UDR0 = '8'; // send '8'
_delay_ms(1000); // 1 second wait
}
return 0;
}