lcd1602驱动

#include<reg52.h>
#define uchar unsigned char
#define uint unsigned int 
sbit wela=P2^1;
sbit dula=P2^0;
sbit dian=P3^5;
sbit RS=P2^4;
sbit RW=P2^3;
sbit E=P2^2;
void delay(uchar z);
void command(uint com);
void write_dat(uchar dat);
void init();
void main()
{
   init();
   write_dat('a');
   delay(20);
   while(1);
}
void delay(uchar z)
{
   uchar x,y;
   for(x=z;x>0;x--)
      for(y=110;y>0;y--)
  ;
}

void command(uint com)
{