BlueTooth HC_05

#include <util/delay.h>
#include <avr/io.h>
#include <avr/interrupt.h>
unsigned char smb = 0;

ISR( USART_RXC_vect )
{
smb = UDR ;
while(!(UCSRA & (1<<UDRE)));
UDR = smb;

}

int main(void) {
UBRRH = 0;
UBRRL = ( F_CPU/( 16UL*9600 ) ) - 1;
UCSRB = (1<<RXCIE)|(1<<RXEN)|(1<<TXEN);
UCSRC = (1<<URSEL)|(1<<UCSZ1)|(1<<UCSZ0);
sei();

// define pd4 as output
// DDRD |= (1 << LED);


while (1) {

_delay_ms(10);

}
return 0;
}