如何测试手里的1602是否可以显示

//ICC-AVR application builder : 2013/11/13 21:45:08

// Target : M16

// Crystal: 7.3728Mhz

#include <iom16v.h>

#include <macros.h>   //??何用



#define uint unsigned int 

#define uchar unsigned char 



#define lcdrs0 PORTA &= ~(1 << 1)//命令

#define lcdrs1 PORTA |= (1 << 1)//数据

#define lcdrw0 PORTA &= (1 << 2)//读

#define lcdrw1 PORTA |= (1 << 2)//写

#define lcden0 PORTA &= ~(1 << 3)//使不能

#define lcden1 PORTA |= (1 << 3)//使能



uchar table[]="I CAN DO IT!^o^";//

uint num;



void busy(void);

void write_date(uchar);

void write_com(uchar);

void init_1602(void);



 void port_init(void)

{

 PORTA = 0x00;

 DDRA  = 0x0E;  //

 PORTB = 0x00;

 DDRB  = 0xff;  //程序原本预计初始化为输出

 PORTC = 0x00; //m103 output only

 DDRC  = 0x00;

 PORTD = 0x00; 

 DDRD  = 0xa7; //本该是0x27

}



void delay(uint z)  

{

 uint x,y;

  for(x=z;x>0;x--)

   for(y=110;y>0;y--);  

}



//有问题

void busy()

{

  uchar mang;

 //lcden0;

 lcdrs0;

 lcdrw1;  //

 //PORTB = 0xff;  //http://www.amobbs.com/thread-4414649-1-1.html 参考其7楼说法

 DDRB=0x00; 

 delay(10);

 lcden1;

 delay(10);

 mang = 0x80;

 delay(10);

 while(mang & 0x80)

 {

  mang = PINB;//忙时为1，禁止读写操作

  mang = PINB;//忙时为1，禁止读写操作

  mang = PINB;//忙时为1，禁止读写操作

  mang = PINB;//忙时为1，禁止读写操作

  delay(10);

 }    

 DDRB=0xFF;

 delay(10);

 lcdrw0;

 delay(10);

 PORTD ^= 0x80;

  delay(300);

}



void write_date(uchar dat)//写数据函数

{ 

 busy();

 lcden0;

 lcdrs1; 

 lcdrw0;

 PORTB=dat; 

 delay(10);

 lcden1; 

 delay(10);

 lcden0; 

} 



void write_com(uchar com)//写命令函数

{ 

 busy();

 lcden0;

 lcdrs0; 

 lcdrw0;

 PORTB = com; 

 delay(10);

 lcden1; 

 delay(20);

 lcden0; 

 delay(100);

 

} 



void init_1602()//1602液晶初始化函数

{ 

 write_com(0x38);//设置1602显示模式为5*7点阵 

 write_com(0x01);//清屏

 write_com(0x0f);//开显示

 write_com(0x06);//设置当读或写一个字符后，地址指针加一，且光标加一 

 write_com(0x80);//设置写数据起始地址

 delay(300);

} 



void main()

{

 port_init();

 delay(1000);

 init_1602();

 for(num=0;num<16;num++)

     write_date(table[num]);

 

 while(1);

}