/* -----------------------       版權聲明      ---------------------------------- 
  ------------------------------ 創新科技   2007/01/05 --------------------------
 
  --------------  Mobile:13433018379  (陶志學) ---------------------------------- 
  ------       Email:taozhixue123@163.com   --------
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  客戶產品上使用本程序時，客戶產品的源程序中必須注明使用了東莞市創新科技的程序，
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 ******************************************************************************** */
//SHTxx程序演示 89 系列 MCU。 時鐘12MHZ
//結果以數碼管顯示


#include <reg51.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             
const unsigned char DATA_7SEG[ ] ={0xc0,0xcf,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};
unsigned char led[6];

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

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

sbit	DATA= P2^3;
sbit	SCK= P2^7;

#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

//----------------------------------------------------------------------------------
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;
}




//delay()________________________________________________
void delay(unsigned char t)
{unsigned char i;
 for (i=0;i<t;i++);
} 
//delay10ms()____________________________________________
void delay10ms(unsigned int count)
{unsigned int i,j,k;
 for(i=0;i<count;i++)
 for(j=0;j<10;j++)
 for(k=0;k<120;k++)
 ;
}
void display(void)
{unsigned char i;
 for (i=0;i<6;i++)
   {P0=~(1<<i);        //低電平驅位選
    P1=DATA_7SEG[led[i]];
    delay(500);    //about 1.5ms
    }
 P0=0xff;
 P1=0xff;
}


//----------------------------------------------------------------------------------
void main()
//----------------------------------------------------------------------------------
// sample program that shows how to use SHT11 functions
// 1. connection reset 
// 2. measure humidity [ticks](12 bit) and temperature [ticks](14 bit)
// 3. calculate humidity [%RH] and temperature [癈]
// 4. calculate dew point [癈]
// 5. print temperature, humidity, dew point  

{ value humi_val,temp_val;
  float dew_point;
  unsigned char error,checksum,Lkeydata0,Lkeydata1,Lkeydata2,Lkeydata3,Lkeydata4,
  Lkeydata5;
  	unsigned int i,j,k;					
					
  P0=0xff;
  P1=0xff;
  init_uart();
  s_connectionreset();
  while(1)
  { error=0;
    error+=s_measure((unsigned char*) &humi_val.i,&checksum,HUMI);  //measure humidity
    error+=s_measure((unsigned char*) &temp_val.i,&checksum,TEMP);  //measure temperature
    if(error!=0) s_connectionreset();                 //in case of an error: connection reset
    else
    { humi_val.f=(float)humi_val.i;                   //converts integer to float
      temp_val.f=(float)temp_val.i;                   //converts integer to float
      calc_sth11(&humi_val.f,&temp_val.f);            //calculate humidity, temperature
      dew_point=calc_dewpoint(humi_val.f,temp_val.f); //calculate dew point
       printf("溫度:%5.1fC 相對濕度:%5.1f%% dew point:%5.1fC\n",temp_val.f,humi_val.f,dew_point);
		
		temp_val.f=temp_val.f*10;
	   temp_val.f=temp_val.f-5;
	   Lkeydata2= temp_val.f/100;

	   Lkeydata1= (temp_val.f-=Lkeydata2*100)/10;

	    Lkeydata0= temp_val.f-=Lkeydata1*10;		
		
		
				   
		humi_val.f=humi_val.f*10;
	   Lkeydata5= humi_val.f/100;

	   Lkeydata4= (humi_val.f-=Lkeydata5*100)/10;

	    Lkeydata3= humi_val.f-=Lkeydata4*10;
	   for (j=0;j<100;j++)
	    {

	     led[2]=Lkeydata2;
		
	     led[1]=Lkeydata1;
	      led[0]=Lkeydata0;
		 	     led[5]=Lkeydata5;
		
	     led[4]=Lkeydata4;
	      led[3]=Lkeydata3;



         for(k=0;k<5;k++)
         display();
		}




    }
    //----------wait approx. 0.8s to avoid heating up SHTxx------------------------------      
    for (i=0;i<10;i++);     //(be sure that the compiler doesn't eliminate this line!)
    //-----------------------------------------------------------------------------------                       
  }
} 

//----------------------------------------------------------------------------------