#include<reg52.h> //Microcontroller specific library, e.g. port definitions
#include <intrins.h> //Keil library (is used for _nop()_ operation)  
#include <math.h>    //Keil library  
#include <stdio.h>   //Keil library
#include <absacc.h>



typedef union 
{ unsigned int i;
  float f;
} value;

//----------------------------------------------------------------------------------
// modul-var
//----------------------------------------------------------------------------------
enum {TEMP,HUMI};

//#define	DATA   	P1_0
//#define	SCK   	P1_1

#define noACK 0
#define ACK   1
                            //adr  command  r/w
#define STATUS_REG_W 0x06   //000   0011    0
#define STATUS_REG_R 0x07   //000   0011    1
#define MEASURE_TEMP 0x03   //000   0001    1
#define MEASURE_HUMI 0x05   //000   0010    1
#define RESET        0x1e   //000   1111    0


#define uchar unsigned char 
#define uint unsigned int 

uchar tplsb,tpmsb;		// 溫度值低位、高位字節(jié) 
uchar ds_num;

unsigned char xdata redata[8];	 
unsigned char xdata sedata[13];


//sbit DQ = P0^1;			// 數(shù)據(jù)通信線DQ

union{
	unsigned int  ds1_temp;   
 	unsigned char  ds1_t[2]; 

}ds1;

union{
	unsigned int  ds2_temp;   
 	unsigned char  ds2_t[2]; 

}ds2;

union{
	unsigned int  ds3_temp;   
 	unsigned char  ds3_t[2]; 

}ds3;


union{
	unsigned int  s_temp;   
 	unsigned char  s_t[2];

}s;

sbit DATA=P1^0;
sbit SCK=P1^1;
//sbit int485=P3^2;
//unsigned char *tm;

//unsigned int s_temph,s_templ,ds_temph,ds_templ;
//float s_tem;
//float xdata ds1_tem,ds2_tem,ds3_tem;


//----------------------------------------------------------------------------------
char s_write_byte(unsigned char value)
//----------------------------------------------------------------------------------
// writes a byte on the Sensibus and checks the acknowledge 
{ 
  unsigned char i,error=0;  
  for (i=0x80;i>0;i/=2)             //shift bit for masking
  { if (i & value) DATA=1;          //masking value with i , write to SENSI-BUS
    else DATA=0;                        
    SCK=1;                          //clk for SENSI-BUS
    _nop_();_nop_();_nop_();        //pulswith approx. 5 us  	
    SCK=0;
  }
  DATA=1;                           //release DATA-line
  SCK=1;                            //clk #9 for ack 
  error=DATA;                       //check ack (DATA will be pulled down by SHT11)
  SCK=0;        
  return error;                     //error=1 in case of no acknowledge
}

//----------------------------------------------------------------------------------
char s_read_byte(unsigned char ack)
//----------------------------------------------------------------------------------
// reads a byte form the Sensibus and gives an acknowledge in case of "ack=1" 
{ 
  unsigned char i,val=0;
  DATA=1;                           //release DATA-line
  for (i=0x80;i>0;i/=2)             //shift bit for masking
  { SCK=1;                          //clk for SENSI-BUS
    if (DATA) val=(val | i);        //read bit  
    SCK=0;  					 
  }
  DATA=!ack;                        //in case of "ack==1" pull down DATA-Line
  SCK=1;                            //clk #9 for ack
  _nop_();_nop_();_nop_();          //pulswith approx. 5 us 
  SCK=0;						    
  DATA=1;                           //release DATA-line
  return val;
}

//----------------------------------------------------------------------------------
void s_transstart(void)
//----------------------------------------------------------------------------------
// generates a transmission start 
//       _____         ________
// DATA:      |_______|
//           ___     ___
// SCK : ___|   |___|   |______
{  
   DATA=1; SCK=0;                   //Initial state
   _nop_();
   SCK=1;
   _nop_();
   DATA=0;
   _nop_();
   SCK=0;  
   _nop_();_nop_();_nop_();
   SCK=1;
   _nop_();
   DATA=1;		   
   _nop_();
   SCK=0;		   
}

//----------------------------------------------------------------------------------
void s_connectionreset(void)
//----------------------------------------------------------------------------------
// communication reset: DATA-line=1 and at least 9 SCK cycles followed by transstart
//       _____________________________________________________         ________
// DATA:                                                      |_______|
//          _    _    _    _    _    _    _    _    _        ___     ___
// SCK : __| |__| |__| |__| |__| |__| |__| |__| |__| |______|   |___|   |______
{  
  unsigned char i; 
  DATA=1; SCK=0;                    //Initial state
  for(i=0;i<9;i++)                  //9 SCK cycles
  { SCK=1;
    SCK=0;
  }
  s_transstart();                   //transmission start
}

//----------------------------------------------------------------------------------
char s_softreset(void)
//----------------------------------------------------------------------------------
// resets the sensor by a softreset 
{ 
  unsigned char error=0;  
  s_connectionreset();              //reset communication
  error+=s_write_byte(RESET);       //send RESET-command to sensor
  return error;                     //error=1 in case of no response form the sensor
}

//----------------------------------------------------------------------------------
char s_read_statusreg(unsigned char *p_value, unsigned char *p_checksum)
//----------------------------------------------------------------------------------
// reads the status register with checksum (8-bit)
{ 
  unsigned char error=0;
  s_transstart();                   //transmission start
  error=s_write_byte(STATUS_REG_R); //send command to sensor
  *p_value=s_read_byte(ACK);        //read status register (8-bit)
  *p_checksum=s_read_byte(noACK);   //read checksum (8-bit)  
  return error;                     //error=1 in case of no response form the sensor
}

//----------------------------------------------------------------------------------
char s_write_statusreg(unsigned char *p_value)
//----------------------------------------------------------------------------------
// writes the status register with checksum (8-bit)
{ 
  unsigned char error=0;
  s_transstart();                   //transmission start
  error+=s_write_byte(STATUS_REG_W);//send command to sensor
  error+=s_write_byte(*p_value);    //send value of status register
  return error;                     //error>=1 in case of no response form the sensor
}
 							   
//----------------------------------------------------------------------------------
char s_measure(unsigned char *p_value, unsigned char *p_checksum, unsigned char mode)
//----------------------------------------------------------------------------------
// makes a measurement (humidity/temperature) with checksum
{ 
  unsigned error=0;
  unsigned int i;

  s_transstart();                   //transmission start
  switch(mode){                     //send command to sensor
    case TEMP	: error+=s_write_byte(MEASURE_TEMP); break;
    case HUMI	: error+=s_write_byte(MEASURE_HUMI); break;
    default     : break;	 
  }
  for (i=0;i<65535;i++) if(DATA==0) break; //wait until sensor has finished the measurement
  if(DATA) error+=1;                // or timeout (~2 sec.) is reached
  *(p_value)  =s_read_byte(ACK);    //read the first byte (MSB)
  *(p_value+1)=s_read_byte(ACK);    //read the second byte (LSB)
  *p_checksum =s_read_byte(noACK);  //read checksum
  return error;
}

//----------------------------------------------------------------------------------
/*void init_uart()
//----------------------------------------------------------------------------------
//9600 bps @ 11.059 MHz 
{SCON  = 0x52;    
 TMOD  = 0x20;    
 TCON  = 0x69;	  
 TH1   = 0xfd;    
}
*/
//----------------------------------------------------------------------------------------
void calc_sth11(float *p_humidity ,float *p_temperature)
//----------------------------------------------------------------------------------------
// calculates temperature [癈] and humidity [%RH] 
// input :  humi [Ticks] (12 bit) 
//          temp [Ticks] (14 bit)
// output:  humi [%RH]
//          temp [癈]
{ const float C1=-4.0;              // for 12 Bit
  const float C2=+0.0405;           // for 12 Bit
  const float C3=-0.0000028;        // for 12 Bit
  const float T1=+0.01;             // for 14 Bit @ 5V
  const float T2=+0.00008;           // for 14 Bit @ 5V	

  float rh=*p_humidity;             // rh:      Humidity [Ticks] 12 Bit 
  float t=*p_temperature;           // t:       Temperature [Ticks] 14 Bit
  float rh_lin;                     // rh_lin:  Humidity linear
  float rh_true;                    // rh_true: Temperature compensated humidity
  float t_C;                        // t_C   :  Temperature [癈]

  t_C=t*0.01 - 40;                  //calc. temperature from ticks to [癈]
  rh_lin=C3*rh*rh + C2*rh + C1;     //calc. humidity from ticks to [%RH]
  rh_true=(t_C-25)*(T1+T2*rh)+rh_lin;   //calc. temperature compensated humidity [%RH]
  if(rh_true>100)rh_true=100;       //cut if the value is outside of
  if(rh_true<0.1)rh_true=0.1;       //the physical possible range

  *p_temperature=t_C;               //return temperature [癈]
  *p_humidity=rh_true;              //return humidity[%RH]
}

//--------------------------------------------------------------------
/*float calc_dewpoint(float h,float t)
//--------------------------------------------------------------------
// calculates dew point
// input:   humidity [%RH], temperature [癈]
// output:  dew point [癈]
{ float logEx,dew_point;
  logEx=0.66077+7.5*t/(237.3+t)+(log10(h)-2);
  dew_point = (logEx - 0.66077)*237.3/(0.66077+7.5-logEx);
  return dew_point;
}
*/

/*****************************************/
/* Copyright (c) 2005, 通信工程學(xué)院      */
/* All rights reserved.                  */
/* 作    者：戴 佳						 */
/*****************************************/

//#include "DigThermo.h"

/* 延時t毫秒 */
void delay(uint t)
{
	uint i;
	while(t--)
	{
		/* 對于11.0592M時鐘，約延時1ms */
		for (i=0;i<125;i++)
		{}
	}
} 

/* 產(chǎn)生復(fù)位脈沖初始化DS18B20 */
void TxReset(void)
{
	uint i;
	P0 = 0x00;

	/* 拉低約900us */
	i = 100;
	while (i>0)	i--;	
	
	P0 = ds_num;				// 產(chǎn)生上升沿
	i = 4;
	while (i>0)	i--;
}

/* 等待應(yīng)答脈沖 */
void RxWait(void)
{
	uint i;
	while(P0);