单片机频率计

#include<reg52.h> unsigned char t=0,yichu=0,fenpin; sbit B153=P2^0; sbit A153=P2^1; sbit GATE=P2^6; sbit CLR=P2^7; sbit P33=P3^3; void t0(void)interrupt 1 {t++; yichu=2; //定时器0溢出，yichu=2 } void t1(void)interrupt 3 //计数器1溢出，yichu=1 {TCON=0; yichu=1; TH1=0xff; TL1=0xff; } void delay(void) //1s软件延时 {unsigned int i=500,j; while(i) {i--; j=250; while(j) {j--;} } } unsigned char table(unsigned char x) //软件查表输出 {unsigned char code n[10]={0xee,0x82,0xdc,0xd6,0xb2,0x76,0x7e,0xc2,0xfe,0xf6}; return(n[x]); } display(float f) //以测出的频率串行输出 {unsigned long x; unsigned char a[5]={0,0,0,0,0},i=0,j; if(f!=0){ if((f<10000)&&(f>1)) //正常显示 {if(f>1000)f=f-1; //软件修正频率偏差 while(f<1000) {f=f*10; i++; } x=f*10; a[4]=x%10; if(a[4]>=5)f=f+1;; x=f; a[1]=x%10; a[2]=(x/10)%10; a[3]=(x/100)%10; a[4]=(x/1000)%10; for(j=0;j<5;j++) {a[j]=table(a[j]);} a[i+1]++; a[0]=0; } else if(f>=10000) //以科学计数法显示 {while(f>=1000) {f=f/10; i++; } x=f; a[4]=(unsigned char)((float)((f-x))*10); if(a[4]>=5)x++; //四舍五入 a[2]=x%10; a[3]=(x/10)%10; a[4]=(x/100)%10; a[0]=i+2; for(j=0;j<5;j++) {a[j]=table(a[j]);} a[4]++; a[1]=0x7c; } else {x=f*10000; //频率值小于1 if((x%10)>=5)x=x+10; //四舍五入 x=x/10; a[1]=x%10; a[2]=(x/10)%10; a[3]=(x/100)%10; a[4]=(x/1000)%10; for(j=0;j<5;j++) {a[j]=table(a[j]);} a[4]++; a[0]=0; } } for(j=0;j<5;j++) //串行 {SBUF=a[j]; while(TI==0);} } cepin() {unsigned char i; float sj; unsigned long js;//时间、计数的拼音首字母 float f; //f为频率 TMOD=0xd9; t=0; TH0=0; TL0=0; TH1=0; TL1=0; GATE=0; TCON=0x50; GATE=1; delay(); GATE=0; for(i=0;i<250;i++){} //延时1ms sj=((float)(TH0*256+t*65536+TL0))/1000000.0; js=(long)TH1*256+TL1+1; f=(js/sj)*fenpin; display(f); } panduan() {float zhouqi; B153=1; A153=1; TMOD=0x51; TH0=0xce; //定时器0=12.8ms TL0=0; TH1=0xff; //计数器1=100个脉冲 TL1=0x9c; TCON=0x50; while(yichu==0); TCON=0; if(yichu==1) //计数器先溢出：在12.8ms内测得的脉冲过多，说明频率较高 {fenpin=128;//转为测128分频后的频率 cepin();} else //计时器先溢出：100个脉冲的时间比较短，即频率较低，可以减少分频数 {yichu=0; B153=1; A153=0; TH0=0xc1; //定时器0=16ms TL0=0x80; TH1=0xff; //计数器1=100个脉冲 TL1=0x9c; TCON=0x50; while(yichu==0); TCON=0; if(yichu==1) //计数器先溢出：在16ms内测得的脉冲过多，说明频率较高 {fenpin=16;//转为测16分频后的频率 cepin();} else //计时器先溢出：100个脉冲的时间比较短，即频率较低，用2分频测周期 {B153=0; //以下是测周期部分 A153=0; TH0=0; TL0=0; t=0; TMOD=0x09; TR0=1; GATE=1; while(P33==0); GATE=0; while(P33==1); TR0=0; zhouqi=(TH0*256+t*65536+TL0)/1000000.0; if(zhouqi<0.001) //若周期太小，则转为测原频率 {fenpin=1; B153=0; A153=0; cepin();} else{display((1.0/zhouqi));} } } } main() { IE=0x8a; while(1) { panduan(); //判断原频率属于哪个范围，并调用相应函数测其频率 delay(); } }