基于52的万用表程序

 #include<reg52.h>  
 #define uchar unsigned char
 #define uint unsigned int
 sbit lcden=P3^4;
 sbit rw= P3^6;    //rw必须要写，不同的单片机初始值不同，rw位必须拉低
 sbit rs= P3^5;
 sbit st=P3^0;   //0809
 sbit oe=P3^1;
 sbit eoc=P3^2;
 sbit clk=P3^3;
 sbit A1=P1^0;
 sbit B1=P1^1;
 sbit C1=P1^2;   // 
 sbit k1=P1^3;
 sbit k2=P1^4;
 //unsigned char channel=0;
 unsigned char num,flaga,flagv,flago=0,adval=0;
 unsigned int count;
 unsigned int b;
 float c;
 unsigned char code table[]={"Voltage 00.00V"};
 unsigned char code table1[]={"Current 000.0mA"};
 unsigned char code table2[]={"Resist 0000ohm"};
 void delay(unsigned int z)
 {
   unsigned x,y;
   for(x=z;x>0;x--)
      for(y=110;y>0;y--); 
 }

 void write_com(unsigned char com) //写指令
 {
   rs=0;
   rw=0;
   lcden=0;
   delay(5); 
   P0=com;
   delay(5);
   lcden=1;
   delay(5);
   lcden=0;  
 }
 void write_date(unsigned char date)   //写数据
 {
   rs=1;
   rw=0;
   lcden=0; 
   delay(5);
   P0=date;
   delay(5);
   lcden=1;
   delay(5);
   lcden=0;
 }

 void init()
 {
 lcden=0; 
 write_com(0x38);
 write_com(0x0c);