疯狂单片机

#include<avr/io.h>
#define fosc 7372800UL //晶振7.3728MHZ
#define baud 9600//波特率
#define com0

void uart0_init(void)
{
     UCSR0B = 0x00; //disable while setting baud rate
     UCSR0A = 0x00;
...