单片机制作的电压表程序

单片机制作的电压表#include<reg52.h>

#include<intrins.h>

#defineucharunsignedchar

#defineuintunsignedint

sfrADC_CONTR=0xBC;//A/D转换功能允许寄存器

sfrADC_RES=0xBD;

//A/D转换结果寄存器

sfrADC_RESL=0xBE;//A/D转换结果寄存器低

sfrAUXR1=0xA2;//辅助寄存器1

sfrP1_ASF=0x9D;

//A/D转换控制寄存器

sbitADIO=P1^7;

//1.7口接测量电压

sbitU3_DS=P1^5;

sbitU3_STCP=P1^4;

sbitU3_SHCP=P1^3;sbitU4_DS=P1^2;

sbitU4_STCP=P1^1;

sbitU4_SHCP=P1^0;

ucharkey_val[]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F','G'};

ucharcodekey_code[]={0x77,0x7B,0x7D,0x7E,0xB7,0xBB,0xBD,0xBE,0xD7,0xDB,0xDD,0xDE,0xE7,0xEB,0xED,0xEE};

ucharkey,count;

voiddelay(unsignedintn);

//74HC595

voidU3_595(unsignedcharnum)

{

unsignedcharcount1;

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;

}

voidU4_595(unsignedcharnum)//发送指令到RS,RW,E(4,5,6位)

{

unsignedcharcount2;

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

voiddelay(unsignedintn)

{

unsignedchari;

for(;n>0;n--)

for(i=0;i<125;i++)

_nop_();

}

//写指令到LCD

voidwcmd(unsignedcharcmd)

{

U4_595(0x0F);

U3_595(cmd);

U4_595(0x4F);

U4_595(0x0F);

}

//写要显示的数据到LCD

voidwdat(unsignedchardat)

{

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

voidinit()

{

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

ucharkeyscan(void)

{

unsignedcharhang,lie,keycode;

chari;

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);

}

voidkeydown()

//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]);

}

}

voidADC_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);

}

voidSET_P1ASF(unsignedcharchannel)//设置模拟功能口

{

unsignedchari,final=0x01;

for(i=0;i<=channel;i++)

final<<=1;

P1_ASF=final;

}

voidSET_ADC_CHANNEL(unsignedcharchannel)//设置A/D转换通道

{

channel|=0xc0;

ADC_CONTR=channel;

delay(100);

}

floatGET_ADC_RESULT()

{

unsignedcharflag=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_FLAGADC_START位

return256*ADC_RES+ADC_RESL;

}

voidmain()

{

floatv;

unsignedtemp,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);d