Question

AVR串口通信程序，在PC端串口助手 一直接收到00

以下是代码，有没有高手指导一下，

//ICC-AVR application builder : 2015/5/8 10:44:16
// Target : m168
// Crystal: 8.0000Mhz

#include <iom168v.h>
#include <macros.h>

void port_init(void)
{
PORTB = 0x00;
DDRB = 0x00;
PORTC = 0x00; //m103 output only
DDRC = 0x00;
PORTD = 0x01;
DDRD = 0x00;
}

//UART0 initialize
// desired baud rate: 9600
// actual: baud rate:9615 (0.2%)
// char size: 8 bit
// parity: Disabled
void uart0_init(void)
{
UCSR0B = 0x00; //disable while setting baud rate
UCSR0A = 0x00;
UCSR0C = 0x06;
UBRR0H = 0x00; //set baud rate hi
UBRR0L = 0x33; //set baud rate lo
UCSR0B = 0x18;

}

//call this routine to initialize all peripherals
void init_devices(void)
{
//stop errant interrupts until set up
CLI(); //disable all interrupts
port_init();
uart0_init();

MCUCR = 0x00;
EICRA = 0x00; //extended ext ints
EIMSK = 0x00;

TIMSK0 = 0x00; //timer 0 interrupt sources
TIMSK1 = 0x00; //timer 1 interrupt sources
TIMSK2 = 0x00; //timer 2 interrupt sources

PCMSK0 = 0x00; //pin change mask 0
PCMSK1 = 0x00; //pin change mask 1
PCMSK2 = 0x00; //pin change mask 2
PCICR = 0x00; //pin change enable
PRR = 0x00; //power controller
SEI(); //re-enable interrupts
//all peripherals are now initialized
}

//字符输出函数
void putchar(unsigned char c)
{
while(!(UCSR0A&(1<<UDRE0)));//判断上次发送有没有完成
UDR0=c;
}

//字符输入函数
unsigned char getchar(void)
{
while(!(UCSR0A&(1<<RXC0)));
return UDR0;
}

//带回车换行控制的字符串输出函数
int puts(char *s)
{
while(*s)
{
putchar(*s);
s++;
}
putchar(0x0a); //回车换行
putchar(0x0d);
return 1;
}

//不带回车换行的字符串输出函数
void putstr(char *s)
{
while(*s)
{
putchar(*s);
s++;
}
}

void main(void)
{
init_devices();
//insert your functional code here...
puts("测试语句");
while(1);

}

Answer 1

刚好调试了M32，我开始收到的和你一样：00这个是十六进制，换成十进制是\0，你可以试试，实际上是熔丝位与你现在期望的频率不匹配造成的，把熔丝位设置为8M的内部晶振就能正确收到数据了。

Answer 2

需要给你写吗

追问

能够指出我这个的问题在哪儿吗？初学没有什么经验。