量程自动切换数字电压表proteus仿真+源程序资料.rar

#include<reg52.h> unsigned char code dispbitcode[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f}; unsigned char dispbuf[4]; unsigned int i; unsigned int j; unsigned int getdata; unsigned int temp; unsigned int temp1; unsigned char count; unsigned char d; sbit ST=P2^4; sbit OE=P2^5; sbit EOC=P2^6; sbit CLK=P2^7; sbit ADD_A=P3^4; //选择AD的输入端 sbit ADD_B=P3^5; sbit ADD_C=P3^6; sbit D0=P2^0; //数码管的位控制端 sbit D1=P2^1; sbit D2=P2^2; sbit D3=P2^3; sbit P17=P1^7; //确定小数点的位置 sbit s1=P3^2; sbit s2=P3^3; #define _v0_5 {s1=1;s2=0;} #define _v10 {s1=0;s2=1;} unsigned char m; void TimeInitial(); void Delay(unsigned int i); void TimeInitial() { TMOD=0x10; TH1=(65536-200)/256; TL1=(65536-200)%256; EA=1; ET1=1; TR1=1; } void Delay(unsigned int i) { unsigned int j; for(;i>0;i--) { for(j=0;j<125;j++) {;} } } void Display() { P1=dispbitcode[dispbuf[3]]; D0=0; D1=1; D2=1; D3=1; Delay(10); P1=0x00; P1=dispbitcode[dispbuf[2]]; if(m==2) { P17=1; } D0=1; D1=0; D2=1; D3=1; Delay(10); P1=0x00; P1=dispbitcode[dispbuf[1]]; if(m==10) { P17=1; } D0=1; D1=1; D2=0; D3=1; Delay(10); P1=0x00; P1=dispbitcode[dispbuf[0]]; D0=1; D1=1; D2=1; D3=0; Delay(10); P1=0x00; } void main() { TimeInitial(); ADD_A=0; ADD_B=0; ADD_C=0; _v10; m=2; while(1) { ST=0; OE=0; ST=1; ST=0; while(EOC==0); OE=1; getdata=P0; OE=0; if ((s1==0) && (s2==1) && (getdata<6)) { ADD_A=1; _v0_5; m=10; } else if ((s1==1)&&(s2==0) && (getdata>254)) { ADD_A=0; _v10; m=2; } temp=(getdata*1.0/255)*500*m; dispbuf[0]=temp%10; dispbuf[1]=temp/10%10; dispbuf[2]=temp/100%10; dispbuf[3]=temp/1000; Display(); } } void t1(void) interrupt 3 using 0 { TH1=(65536-200)/256; TL1=(65536-200)%256; CLK=~CLK; }