#include "reg52.h"

unsigned char  code Duan[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,
	  0x6f,0X76,0X3e,0x55,0x37,0x77,0x5e,0x72};
unsigned char  Data_Buffer[4]={1,2,0,0};

unsigned char PinLV_Out=10;//范圍:10-90hz
unsigned char PinLV_In=0;

unsigned char th0,tl0;

sbit P10=P1^0;
sbit P11=P1^1;
sbit P12=P1^2;
sbit P13=P1^3;

sbit P23=P2^3;
sbit P32=P3^2;

sbit DOWN=P2^2;
sbit UP=P2^1;

bit flag=0;
unsigned char temp_th1,temp_tl1;
unsigned char count_t1=0,temp_count=0;

void Comute_pinlv()
{
 float t;
 unsigned int x;
 t=1000/PinLV_Out/2;//計算高\低寬度時間ms為單位
 t=t*921.6;
 t=65535-t;
 x=t;
 th0=x/256;
 tl0=x%256;
 
 Data_Buffer[0]=PinLV_Out/10;
 Data_Buffer[1]=PinLV_Out%10;
}

void main()
{	

    unsigned char Bit=0;
    unsigned int xx;
 	float t;
	bit x=1,y=1;

	Comute_pinlv();
   	
	TMOD=0x11;
	TH0=th0;
	TL0=tl0;
 	TR0=1;
	ET0=1;
 	EA=1;
	IT0=1;
	EX0=1;

	TR1=1;
    ET1=1;

    while(1)  
    {
       if(UP==1)x=1;//頻率增加
	   else if(x==1)
	   {
	      x=0;
			PinLV_Out+=5;
			if(PinLV_Out>90)PinLV_Out=90;
			Comute_pinlv(); //計算輸出頻率的定時器值
	   }
	   
	   if(DOWN==1)y=1;//頻率減小
	   else if(y==1)
	   {
	      y=0;
		    if(PinLV_Out>10)
			PinLV_Out-=5;
			Comute_pinlv();
	   }
	  
	   if(flag)//重新計算頻率
	   {
	    flag=0;
 		xx=temp_th1*256+temp_tl1;
 		t=xx+temp_count*65536;
 		t=t/921.6;//921.6代碼對應1ms
 		t=1000/t;
 		PinLV_In=t;
 		Data_Buffer[2]=PinLV_In/10;//計算的頻率在后兩位數碼管顯示
 		Data_Buffer[3]=PinLV_In%10;
	   }


    	Bit++;//數碼管掃描
 		if(Bit>=4)Bit=0;
 		P1|=0x0f;
	 	P0=Duan[Data_Buffer[Bit]];
 		switch(Bit)
 		{
 		 case 0: P10=0;break;
 		 case 1: P11=0;break;
 		 case 2: P12=0;break;
  		 case 3: P13=0;break;
 		}
    }
}

void timer0() interrupt 1 //方波發生定時器
{
 TH0=th0;
 TL0=tl0;

 P23=!P23;//方波輸出
 P32=P23;//實際當中應用線連接 
}

void int0() interrupt 0 //外部中斷，P32作測頻。
{ 
 flag=1;  //需要更新頻率，即重新計算頻率值
 temp_th1=TH1;//臨時存儲計頻數據
 temp_tl1=TL1;
 temp_count=count_t1;

 TH1=0; //重新置0,重新啟動方波寬度時間計時
 TL1=0;
 count_t1=0;
}

void timer1() interrupt 3
{
   count_t1++;
}