单片机制作的电压表程序.doc

单片机制作的电压表
#include <reg52.h>
#include <intrins.h>
#define uchar unsigned char
#define uint unsigned int
sfr ADC_CONTR=0xBC; //A/D转换功能允许寄存器
sfr ADC_RES=0xBD;   //A/D转换结果寄存器
sfr ADC_RESL=0xBE; //A/D转换结果寄存器低
sfr AUXR1=0xA2; //辅助寄存器1
sfr P1_ASF=0x9D;    //A/D转换控制寄存器
sbit ADIO=P1^7;       //1.7口接测量电压
sbit U3_DS=P1^5;
sbit U3_STCP=P1^4;
sbit U3_SHCP=P1^3;
sbit U4_DS=P1^2;
sbit U4_STCP=P1^1;
sbit U4_SHCP=P1^0;
uchar key_val[]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F','G'};
uchar code key_code[]={0x77,0x7B,0x7D,0x7E,0xB7,0xBB,0xBD,0xBE,0xD7,0xDB,0xDD,0xDE,0xE7,0xEB,0xED,0xEE};
uchar key,count;
void delay(unsigned int n);
//74HC595
void U3_595(unsigned char num)
    {
   unsigned char count1;
   for (count1=0;count1<=7;count1++)
       {
       if ((num&0x80)==0x80)//最高位为1，则向SDATA_595发送1
      {
             U3_DS=1;
    }
             else
     {
             U3_DS=0;
    }
    U3_SHCP=0;
    U3_SHCP=1;
             num<<=1;//左移
    }
U3_STCP=0;
U3_STCP=1;
}
void U4_595(unsigned char num)//发送指令到RS,RW,E(4,5,6位)
    {
   unsigned char count2;
    for (count2=0;count2<=7;count2++)
       {
             if((num&0x80)==0x80)
      {
             U4_DS=1;
    }
             else
    {
             U4_DS=0;
    }
             U4_SHCP=0;
    U4_SHCP=1;
       num<<=1;
     }
    U4_STCP=0;
    U4_STCP=1;
}
//LCD延时子程序 n=1时延时1ms
void delay(unsigned int n)
   {
      unsigned char i;
      for(;n>0;n--)
      for(i=0;i<125;i++)
         _nop_();
}
//写指令到LCD
void wcmd(unsigned char cmd)
{
    U4_595(0x0F);
U3_595(cmd);
    U4_595(0x4F);
U4_595(0x0F);
}
//写要显示的数据到LCD
void wdat(unsigned char dat)
{
    U4_595(0x1F);//低4位全为1屏蔽8段数码管
   U3_595(dat);
U4_595(0x5F);
U4_595(0x1F);
}
//初始化LCD
void init()
{
    wcmd(0x38);//设置8位总线双行显示，5*7点阵
   delay(20);
wcmd(0x0C);//开显示，开光标，不闪烁
delay(20);
wcmd(0x06);//读写字符时地址加1
delay(20);
wcmd(0x01);//清屏
delay(20);
wcmd(0x82);
}
//键盘扫描子程序
uchar keyscan(void)
{
     unsigned char hang,lie,keycode;
char i;
P0=0xf0;
hang=P0;
    if((hang&0xf0)!=0xf0)           //有键按下？
    {
    delay(5);                   //去抖动
      hang=P0;
    if((hang&0xf0)!=0xf0)         //有键按下
     {   
                P0=0x0f;
     lie=P0;
     keycode=hang|lie;         //获得键码
     for(i=15;i>=0;i--)
       {
       if(keycode==key_code[i]) //查找键码
       {
          key=i;
          return(key);
        }
                    }
               }
           }
        else
   return (key);
}
void keydown()                     //判断按键按下和显示程序
{
    P0=0xf0;
if((P0&0xf0)!=0xf0)
   {    
        while(P0!=0xf0)
   keyscan();                  //获得键码
        wcmd(0xCF);       //设置键值显示位置
   wdat(key_val[16-key]);
       }
}
void ADC_POWER_ON() //开ADC电源，第一次使用要打开内部模拟电源
{
ADC_CONTR=0x80;
delay(10);
}
void SET_P1ASF(unsigned char channel) //设置模拟功能口
{
    unsigned char i,final=0x01;
for(i=0;i<=channel;i++)
    final<<=1;
P1_ASF=final;
}
void SET_ADC_CHANNEL(unsigned char channel) //设置A/D转换通道
{
     channel|=0xc0;
     ADC_CONTR=channel;
delay(100);
}
float GET_ADC_RESULT()
{
    unsigned char flag=0x10,temp=0x00;
   ADC_RES=0x00;
ADC_RESL=0x00;
AUXR1=0x04;//设置10位AD
ADC_CONTR|=0x08;//启动A/D转换
_nop_();
_nop_();
_nop_();
_nop_();
do {temp=flag&ADC_CONTR;} while (temp==0x00);
ADC_CONTR=ADC_CONTR&0xc7; //清零ADC_FLAG ADC_START 位
return 256*ADC_RES+ADC_RESL;
}
void main()
{
   float v;
   unsigned temp,temp1,temp2;
   init();
   ADC_POWER_ON();
   while(1)
     {
     key=keyscan();
        keydown();
    if(16-key==1)   //量程5V
    {          
     SET_P1ASF(6);
        SET_ADC_CHANNEL(6);
        v=GET_ADC_RESULT();
        v=v*5/1024;
        temp=v;
        wcmd(0x82);delay(5000);
        wdat(0x30+temp);
        temp1=(v-temp)*10;
        wdat(46);//小数点
        wdat(0x30+temp1);
        temp2=(v-temp)*100-temp1*10;
        wdat(0x30+temp2);
     wdat(86);//V
     wdat(32);//空白
       }
   if(16-key==2) //量程5-20V
   {          
     SET_P1ASF(6);
        SET_ADC_CHANNEL(6);
        v=GET_ADC_RESULT();
        v=4*v*5/1024;
     temp=v/10;
        wcmd(0x82);delay(5000);
     wdat(0x30+temp);
     temp1=(int)v%10;
     wdat(0x30+temp1);
     wdat(46);//小数点
        temp2=v*10;
        wdat(0x30+temp2%10);
     temp2=v*100;
     wdat(0x30+temp2%10);
     wdat(86);//V
    }
    if(16-key==3) //量程20-100V
   {
     SET_P1ASF(6);
        SET_ADC_CHANNEL(6);
        v=GET_ADC_RESULT();
        v=19.8*5*v/1024;
     temp=v/10;
        wcmd(0x82);delay(5000);
        wdat(0x30+temp);
        temp1=v-temp*10;
        wdat(0x30+temp1);
     wdat(46);//小数点
        temp2=v*10;
        wdat(0x30+temp2%10);
     temp2=v*100;
     wdat(0x30+temp2%10);
     wdat(86);//V
    }
}
}