基于单片机的数字电压表的设计c语言.doc

#includereg52.h #includeintrins.h sbit st=P2^4; sbit eoc=P3^7; sbit oe=P2^5; sbit ale=P2^3; sbit key1=P3^6; sbit key2=P3^5; unsigned char seg_code[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90}; unsigned char seg_ale[]={0xf8,0xf9,0xfa,0xfb}; unsigned char num[4]; /************延时函数**********************/ void delay_us(unsigned int delayus) { while(delayus--); } void delay_ms(unsigned int delaytime) { unsigned int i; unsigned char j; for(i=0;idelaytime;i++) for(j=0;j110;j++); } /********************************************/ /************ADC转换函数*********************/ void adc_convert(void) { double temp1; unsigned int temp2,temp3; st=0; _nop_(); st=1; _nop_(); st=0; oe=0; while(eoc==0); oe=1; _nop_(); temp1=P0; _nop_(); temp1*=492; //基准电压 4.9 V temp1/=255; temp2=(unsigned int)temp1%1000; num[2]=(unsigned char)(temp2/100); temp3=(unsigned int)temp2%100; num[1]=(unsigned char)(temp3/10); num[0]=temp3%10; delay_us(1); oe=0; } /*******************************************/ /**************显示函数*********************/ void dis(void) { unsigned char i,b; b=0x01; for(i=0;i4;i++) { if(i==2) P1=seg_code[num[i]]0x7f; else if(i==3) P1=seg_code[num[i]]0x7f; else P1=seg_code[num[i]]; P3=~b; b=1; delay_ms(5); } } /*******************************************/ /****************主函数*********************/ void main(void) { unsigned char i,automatic; unsigned char keynum; int j; for(i=0;i4;i++) num[i]=0; keynum=0; for(;;) { /**************按键扫描******************************/ if(key1==0) { delay_ms(1); dis(); delay_ms(1); dis(); delay_ms(1); dis(); delay_ms(1); dis(); delay_ms(1); dis(); delay_ms(1); dis(); delay_ms(1); dis(); if(key1==0) { if(keynum3) keynum++; else keynum=0; } } if(key2==0) //自动加按键 {