/*串口初始化函數(shù)*/ //使用同一個(gè)串口進(jìn)行發(fā)送與接收，mega162具有雙串口功能
void Uart_Init(void)

{
UCSRA = 0x02;/*倍速*/
UCSRB = 0x18;/*允許接收和發(fā)送*/
UCSRC = 0x06;/*8位數(shù)據(jù)*/
UBRRH = 0x00;
UBRRL = 12;/*9600*/
}

/*數(shù)據(jù)發(fā)送，查詢方式*/
void Uart_Transmit(unsigned char i)

{

while (!(UCSRA & (1<UDR = i;/* 發(fā)送數(shù)據(jù)*/
}

/*數(shù)據(jù)接收，查詢方式*/
unsigned char Uart_Receive( void ) //注意函數(shù)類型

{

while (!(UCSRA & (1<return UDR;/* 獲取并返回?cái)?shù)據(jù)*/
}

/*主函數(shù)*/
void main(void)

{

unsigned char temp;

DDRA = 0x00;/*方向輸入*/
PORTA = 0xFF;/*打開(kāi)上拉*/
DDRB = 0xFF;/*方向輸出*/
PORTB = 0xFF;/*電平設(shè)置*/
DDRC = 0x00;
PORTC = 0xFF;
DDRD = 0x02;
PORTD = 0xFF;
Uart_Init();

while (1)

{
temp = Uart_Receive();/*等待接收數(shù)據(jù)*/
PORTB = ~temp;/*顯示低電平有效*/
Uart_Transmit(temp);/*發(fā)送收到的數(shù)據(jù)*/
}
}