#include "reg51.h"
#include "stdio.h"
#include " absacc.h "
#include <intrins.h>
#include <math.h>


/********************************************************************/
void delay_nms(unsigned int n);//delay function

sbit F_in=P3^6;  //測量頻率管腳
sbit F_out=P3^7; //發生頻率管腳

bit int_flag;
unsigned int frequency;

void Display(void);
void Mcu_init(void);
void Measure_F(void);
void Measure_T(void);
void Frequency_Measure(void);


/***********************************************************************/     

/********************/
sbit  RCLK = P2^5;
sbit  SCLK = P2^6;
sbit  SDAT = P2^7;

sbit  A_SEL = P2^2;
sbit  B_SEL = P2^3;
sbit  C_SEL = P2^4;

#define		SM0		A_SEL = 0;	B_SEL = 0;	C_SEL = 0
#define		SM1		A_SEL = 1;	B_SEL = 0;	C_SEL = 0
#define		SM2		A_SEL = 0;	B_SEL = 1;	C_SEL = 0
#define		SM3		A_SEL = 1;	B_SEL = 1;	C_SEL = 0
#define		SM4		A_SEL = 0;	B_SEL = 0;	C_SEL = 1
#define		SM5		A_SEL = 1;	B_SEL = 0;	C_SEL = 1
#define		SM6		A_SEL = 0;	B_SEL = 1;	C_SEL = 1
#define		SM7		A_SEL = 1;	B_SEL = 1;	C_SEL = 1

unsigned char leddata[]={ 
 
                0x3F,  //"0"
                0x06,  //"1"
                0x5B,  //"2"
                0x4F,  //"3"
                0x66,  //"4"
                0x6D,  //"5"
                0x7D,  //"6"
                0x07,  //"7"
                0x7F,  //"8"
                0x6F,  //"9"
                0x77,  //"A"
                0x7C,  //"B"
                0x39,  //"C"
                0x5E,  //"D"
                0x79,  //"E"
                0x71,  //"F"
                0x76,  //"H"
                0x38,  //"L"
                0x37,  //"n"
                0x3E,  //"u"
                0x73,  //"P"
                0x5C,  //"o"
                0x40,  //"-"
                0x00,  //熄滅
                0x00  //自定義
 
                         };

void send(unsigned char data_out)
{
	unsigned char i;
	RCLK = 0;
	
	for(i=0;i<8;i++)
	{
		if( data_out & 0x80)
			SDAT = 1;
		else
			SDAT = 0;
		SCLK = 0;
		
		SCLK = 1;
		
		data_out =  data_out<<1;	  
	}
	RCLK = 1;
}

#define		delay		450



/***********************************************************************/
void dis_delay(void);
void display(unsigned int temp);
/***********************************************************************/

void display(unsigned int temp) 
{   
	unsigned int i;

	//send(0x00);

	SM6;
 	send(0x40);
 	for(i = 0; i < delay; i++);
	send(0x00);
	 
	SM7;
	if(frequency<2000)
 		send(0x39);
	else
		send(0x71);
 	for(i = 0; i < delay; i++);
	send(0x00);
	
	SM0;
 	send(leddata[temp/1000%10]);
 	for(i = 0; i < delay; i++);
	send(0x00);

	SM1;
 	send(leddata[temp/100%10]);
 	for(i = 0; i < delay; i++);
	send(0x00);

	SM2;
 	send(leddata[temp/10%10]);
 	for(i = 0; i < delay; i++);
	send(0x00);

	SM3;
 	send(leddata[temp%10]);
 	for(i = 0; i < delay; i++);
	send(0x00);


}
 
void main()
{ 
 Mcu_init();   //初始化
  
 while(1)    
 {
 unsigned int i;  
 Frequency_Measure();
 
 
 for(i=100;i>0;i--)
    display(frequency);
 }
}

void time0(void)  interrupt 1 
{
 int_flag=1; //計數溢出標志
}

void time1(void)  interrupt 3 
{
 TH1=0xfe; //重新附值
 TL1=0x33;
 F_out=!F_out; //取反 產生頻率
}

void Frequency_Measure(void)   
{
 if(frequency<2000)   //小于 2k 測周
  Measure_T();
 else if(frequency>=2000) //大于2k 測頻
  Measure_F();
}

//測頻原理：
//開一個標準的50ms計數閘門，對被測信號計數
void Measure_F(void)  //測頻子函數
{
 bit state_old=0,state_new=0; //定義狀態
 unsigned int f_count=0;   //計數臨時值
 int_flag=0;
 TH0=0x4c; //定時器初值 50ms
 TL0=0x00;
 TR0=1;  //啟動計數器
 while(1)  //死循環 測頻
 {
  state_new=F_in; //取得現在的 頻率發生引腳狀態
  if(state_old!=state_new) //與前一個時刻 舊值 比較，如果不同
   f_count++;  //則 計數加1
  state_old=state_new; //將新值 付給 舊值
  if(int_flag)  //如果到了定時時間
  { 
   TR0=0;  //關閉定時器0 
   frequency=f_count*10; //計算頻率
      //定時 50ms計數 每個周期 計2次 所以 1s內計數= f_count*10
   return;  //返回 跳出循環
  }
 }
}

//原理：以被測信號的一個周期為閘門
//對單片機及其周期進行計數 讀取定時器的值為計數值
void Measure_T(void) //測周子函數
{ 
 bit state_old=0,state_new=0; //定義狀態
 unsigned char temp_flag=0;
 unsigned int t_count;   //計數臨時值
 
 TH0=0;
 TL0=0;
    while(1) //死循環 測周
    {
      state_new=F_in; //取得現在的 頻率發生引腳狀態
        if(state_old&&!state_new)  // 下降沿開始啟動閘門
        {
         temp_flag++;   
         TR0=1;  //啟動定時器 計數
        }
        if(temp_flag==2)
        {
         TR0=0;   //計數停止
         t_count=TH0*256+TL0;  //取得當前的計數值
         frequency=1000000/t_count;  //計算頻率
         return;  //返回
        }
        state_old=state_new;
 }
}


void Mcu_init(void) //初始化函數
{
 EA=1;  //開總中斷
 ET0=1;  //定時器0 開
 TR0=1;    //啟動定時器 0
 ET1=1;  //定時器 1 開
 TR1=1;  //啟動定時器1 
 TMOD=0x11;  //工作狀態
 TH0=0x4c; //定時器初值
 TL0=0x00;
 TH1=0xfe;
 TL1=0x33;

}