STC89C52实现在LCD1602液晶屏上显示AD模块中的电位器的电压遇到问题

Question

我用的是普中51双核A6开发板，STC89C52芯片，我首先编写了LCD1602显示AD模块中的电位器电压，我用电位器调节，一切正常，显示范围是0-5V。

但是我现在想用单片机产生的PWM波来控制这个电压，我设定PWM波为10KHZ，占空比为10%，可是LCD1602显示却变为了3.125V，我调整电位器，这个数字一直不变，10%的占空比，不应该最大显示为0.5V吗？

下面是我的主程序：

#include"reg52.h"
#include"lcd.h"
sbit PWM=P2^1;
sbit add=P3^1;
sbit dec=P3^0;
typedef unsigned int u8;
typedef unsigned char u16;
typedef unsigned long u32;
void delay(u16 i)
{
     while(i--);
}
#define SYSCLOCK 12000000
u8 disp[4]={0,0,0,0};
u16 Volt;
u8 highHR0,highLR0;
u8 lowHR0,lowLR0;
u8 cont=10;
void datapros()
{    u16 temp;
     static u8 i;
     if(i==50)
     {i=0;
      temp=Read_AD_Data(0x94);
     }
     i++;
     Volt=temp*5/4096.0*1000+0.5;
     disp[0]=Volt/1000;
     disp[1]=Volt%1000/100;
     disp[2]=Volt%1000%100/10;
     disp[3]=Volt%1000%100%10;
}
void PWM_Config(u16 fr,u8 dc)
{    u32 tmp;
     u16 high,low;
     tmp=SYSCLOCK/12;
     tmp=tmp/fr;
     high=(tmp*dc)/100;
     low=tmp-high;
     high=65536-high;
     low=65536-low;
     highHR0=(u8)(high>>8);
     highLR0=(u8)high;
     lowHR0=(u8)(low>>8);
     lowLR0=(u8)low;
     TMOD&=0XF0;
     TMOD|=0X10;
     TH1=highHR0;
     TL1=highLR0;
     PWM=1;
     TR1=1;
     ET1=1;
     EA=1;
}
void PWM_Close()
{    TR1=0;
     ET1=0;
     PWM=1;
}
void ADD()
{    if(add==0)
     {delay(1000);
      if(add==0)
     {cont+=10;
      if(cont>=50)
      {cont=50;}
     }
     while(!add);
     }
}
void DEC()
{    if(dec==0)
     {delay(1000);
      if(dec==0)
     {cont-=10;
      if(cont<=10)
      {cont=10;}
     }
     while(!dec);
     }
}

void main()
{u16 i;
 LcdInit();
 while(1)
 {datapros();
  LcdWriteCom(0x80);
  LcdWriteData("V");
  LcdWriteCom(0x81);
  LcdWriteData("o");
  LcdWriteCom(0x82);
  LcdWriteData("u");
  LcdWriteCom(0x83);
  LcdWriteData("t");
  LcdWriteCom(0x84);
  LcdWriteData("=");
  LcdWriteCom(0x85);
  for(i=0;i<4;i++)
  {LcdWriteData("0"+disp[i]);
   if(i==0)
   LcdWriteData(".");
  }
  LcdWriteCom(0x8a);
  LcdWriteData("V");
  PWM_Config(13158,cont);
  for(i=0;i<30000;i++);
  ADD();
  DEC();
  PWM_Close();
 }
}
void Timer0_ISP() interrupt 3
{    if(PWM)
     {TH1=lowHR0;
      TL1=lowLR0;
      PWM=0;
     }
     else
     {TH1=highHR0;
      TL1=highLR0;
      PWM=1;
     }
}

就是感觉XPT2046芯片转换的AD模块电位器的电压和单片机芯片产生的PWM波无法关联，怎么用PWM波占空比控制（AD模块转换出的）电位器电压从而显示在液晶屏上？求指导！！！！

Answer 1

参考

https://blog.csdn.net/Is_Superman/article/details/108421606?utm_medium=distribute.pc_aggpage_search_result.none-task-blog-2~aggregatepage~first_rank_v2~rank_aggregation-3-108421606.pc_agg_rank_aggregation&utm_term=51%E5%8D%95%E7%89%87%E6%9C%BAad%E8%BD%AC%E6%8D%A2c%E8%AF%AD%E8%A8%80%E7%A8%8B%E5%BA%8F&spm=1000.2123.3001.4430