M16 Temperature Sensor DS18B20 Control Example Program

//DS18b20 C language driver, three-digit digital tube display, read the current ambient temperature, accuracy of 0.1 degrees, temperature range 0-99 degrees 
//DS18B20 detailed pin function description 1. GND ground signal; 2. DQ data input and output pin. Open drain single bus interface pin. When used under parasitic power supply 
//It can also provide power to the device; 3. VDD optional VDD pin. When working under parasitic power supply, this pin must be grounded. 
//How to use DS18B20. DS18B20 uses 1-Wire bus protocol 

: //That is, to realize bidirectional transmission of data on one data line 
//Compilation environment AVR Studio 4.13/AVR GCC 
//System clock 7.3728MHz, set the fuse bit to external high-frequency quartz crystal oscillator, startup time 4.1ms   //  ***********************************************************************  //  
Include 
files 
//*********************************************************************** 

#include  
#include #include <  string.h > #include #include   #include   #include   #include //Interrupt signal header file  //*******************************************************************************  // Define variable area  // CH451 various function command values, write as needed  //*******************************************************************  #define CH451_RESET 0x0201 //Reset  #define CH451_LEFT MOV 0x0300 //Set the movement mode - left shift  #define CH451_LEFTCYC 0x0301 //Set the movement mode - left cycle  #define CH451_RIGHT MOV 0x0302 //Set the movement mode - right shift  #define CH451_RIGHTCYC 0x0303 //Set the movement mode - right cycle   #define CH451_SY SOF F 0x0400 //Turn off display, keyboard, watchdog  #define CH451_SYSON1 0x0401 //Turn on display  #define CH451_SYSON2 0x0403 //Turn on display and keyboard  #define CH451_SYSON3 0x0407 //Open the display, keyboard and watchdog functions  #define CH451_ DSP        0x0500 //Set the default display mode  #define CH451_BCD 0x0580 //Set the BCD decoding mode  #define CH451_TWINKLE 0x0600 //Set the blinking control  #define CH451_DIG0 0x0800 //Display the digital tube position 0  #define CH451_DIG1 0x0900 //Display the digital tube position 1   #define CH451_DIG2 0x0a00 //Display the digital tube position 2  #define CH451_DIG3 0x0b00 //Display the digital tube position 3  #define CH451_DIG4 0x0c00 //Display the digital tube position 4  #define CH451_DIG5 0x0d00 //Display the digital tube position 5   #define CH451_DIG6 0x0e00 //Display of digital tube position 6   #define CH451_DIG7 0x0f00 //Display of digital tube position 7  #define  LED 0 0x0000 //Data displayed by digital tube position 0  #define led1 0x0000 //Data displayed by digital tube position 0; 0x0010 means off  #define led2 0x0000 //Data displayed by digital tube position 0  #define led3 0x0010 //Data displayed by digital tube  position 0#define led4 0x0010 //Data displayed by digital tube position 0  #define led5 0x0010 //Data displayed  by digital tube position 0#define led6 0x0010 //Data displayed by digital tube position 0  #define led7 0x0010 //Data displayed by digital tube position 0  #define dclk0 PORTD &= ~(1 << PD6) //Serial data clock, rising delay activation  #define dclk1 PORTD |= (1 << PD6)  #define din0 PORTD &= ~(1 << PD5) //Serial data output, connected to CH451 data input  #define din1 PORTD |= (1 << PD5) 












































#define load0 PORTD &= ~(1 << PD4) //Serial command loading, rising delay activation 
#define load1 PORTD |= (1 << PD4) 

#define DQ_IN DDRC &= ~(1 << PC6) //Set input 
#define DQ_OUT DDRC |= (1 << PC6) //Set output 
#define DQ_CLR PORTC &= ~(1 << PC6) //Set low level 
#define DQ_SET PORTC |= (1 << PC6) //Set high level 
#define DQ_R          PIN C & (1 << PC6) //Read level 


#define delay_us(x) _delay_us(x) //AVR GCC delay function x(us) 
#define delay_ms(x) _delay_ms(x) //AVR GCC delay function x(ms) 

#define uchar unsigned char 
#define uint unsigned int 
uint value; 
uint temp,A1,A2,A3; //Defined variables, display data processing 
uchar flag1;             
uchar table[]={0x00,0x01,0x02,0x03,0x04,0x05,0x06, 
               0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d, 
     0x0e,0x0f}; //BCD code of digital tube 


//**************************************************************************** 
// Initialization subroutine 
//**************************************************************************** 

void system_init() 
{ 

SFIOR=(1<<2)|SFIOR; //PUD=1; turn off the pull-up resistor 
PORTD=0x70; 
DDRD=0x70; 

} 

void ch451_init() 
{ 
  din0; //first low then high, select 4-wire input 
  din1; 

} 
//**************************************************************************** 
// Output command subroutine 
// Define an unsigned integer variable to store 12 bytes of command word 
 //******************************************************************** 
  void ch451_write(unsigned int command) 
{ 
  unsigned char i; 
  load0; // Command start        
  for(i=0;i<12;i++) 
   { // Input 12 bits of data, low bit firstif 
      
     (command&1) 
  { 
    din1; 

  } 
  else 
    din0;  
     dclk0; 
     dclk1; // Rising edge valid 
     command>>=1;                                 
   } 
     load1; // Load data 

} 

//************************************************************************* 
// Display function 
//********************************************************************* 
void display(uint b_d,uint s_d,uint g_d) 
{ 
 ch451_init(); 
 ch451_write(CH451_SYSOFF); //Turn off display, keyboard, and watchdog 
 ch451_write(CH451_SYSON1); //Turn on display 
 ch451_write(CH451_BCD); //Set BCD decoding mode 
 ch451_write(CH451_TWINKLE); //Set twinkle control  

 ch451_write(CH451_DIG0|table[b_d]); //Display hundreds digit 
 datach451_write(CH451_DIG1|table[s_d]|0x80); //Display tens digit 
 datach451_write(CH451_DIG2|table[g_d]); //Display units digit  
 datach451_write(CH451_DIG3|led3); //Other digital tubes are not displayed and are offch451_write 
 (CH451_DIG4|led4); 
 ch451_write(CH451_DIG5|led5); 
 ch451_write(CH451_DIG6|led6); 
 ch451_write(CH451_DIG7|led7); 

} 

  
//*************************************************************************  
// DS18B20 initialization 
//************************************************************************ 

unsigned char ds1820_reset(void) //initialization and reset 

{ 
unsigned char i; 
        DQ_OUT; 
 DQ_CLR; 
 delay_us(500); //delay 500uS(480-960) 
 DQ_SET; 
 DQ_IN; 
 delay_us(80); //delay 80uS 
 i = DQ_R; 
 delay_us(500); //delay 500uS(keep>480uS) 
  
 if (i)  
        { 
  return 0x00; 
   
        } 
 else  
        { 
  return 0x01; 
   
        } 

} 


//*****************************************************************************  
// DS18B20 read a byte function 
//*************************************************************************  
    
unsigned char ds1820_read_byte(void)  
{ 

 unsigned char i; 
 unsigned char value = 0; 
 for (i = 8; i != 0; i--)  
        { 
  value >>= 1; 
  DQ_OUT; 
  DQ_CLR; 
                delay_us(4); //*Delay 4uS 
   
  DQ_SET; 
  DQ_IN; 
                delay_us(10); //*Delay 10uS 
   
  if (DQ_R)  
                { 
   value|=0x80; 
    
                } 
  delay_us(60); //*Delay 60uS 
   
        } 
  
 return(value); 
} 

//*****************************************************************************  
// Write a byte function to 18B20 
//*************************************************************************   

/*DS18B20 byte write function*/ 
void ds1820_write_byte(unsigned char value)  
{ 

 unsigned char i; 
 for (i = 8; i != 0; i--)  
        { 
  DQ_OUT; 
  DQ_CLR; 
                delay_us(4); //delay 4uS 
  if (value & 0x01)  
                { 
   DQ_SET; 
    
                } 
  delay_us(80); //delay 80uS 
  DQ_SET; //bit end 
  value >>= 1; 
   
        } 
  
} 
//************************************************************************ 
// Send temperature conversion command 
//****************************************************************************  

/*Start ds1820 conversion*/ 
void ds1820_start(void) { 

 ds1820_reset(); 
 ds1820_write_byte(0xCC); //Do not omit address 
 ds1820_write_byte(0x44); //Start conversion 
} 

//***************************************************************************** 
// DS8B20 reads temperature information 
//*****************************************************************************  

unsigned int ds1820_read_temp(void)  
{ 

 unsigned int i; 
 unsigned char buf[9]; 

 ds1820_reset(); 
 ds1820_write_byte(0xCC); //Do not omit address 
 ds1820_write_byte(0xBE); //Read temperaturefor 
 (i = 0; i < 9; i++)  
        { 
  buf[i] = ds1820_read_byte(); 
   
        } 
 i = buf[1]; 
 i <<= 8; 
 i |= buf[0]; 
 value=i; 
        value=value*0.625; //The reason for not multiplying by 0.0625 is to convert the data after the decimal point into data that can be displayed 
                          . //For example, the temperature itself is 27.5 degrees. In order to get the BCD code in the subsequent data processing program, we first enlarge it to 275. 
                                        //Then determine the position of the decimal point when displaying, and 27.5 degrees can be displayed. 
        //value=value*10; 
 return i; 
} 

  

//******************************************************************************** 
// Temperature data processing function 
//**************************************************************************** 
 void data_do(uint d) 
 { 
     uint A2t; 
     A1=d/100; //Separate hundreds, tens, and onesA2t 
     =d%100; 
     A2=A2t/10; 
     A3=A2t%10; 
} 

//**************************************************************************** 
// Main program 
//**************************************************************************** 

void main(void) 
{ 

 DDRC = 0x00; 
 PORTC = 0xFF; 
 system_init(); //System initialization 
 delay_ms(250);  
 ds1820_reset(); //Reset D18B20 
 while (1) 
        { 
  ds1820_start(); //Start a conversion 
  delay_ms(300); //Wait for the conversion to end 
  ds1820_read_temp(); //Read the temperature value 
        data_do(value); //Process the data and get the value to be displayed 
     display(A1,A2,A3); //Display the temperature value 
     delay_ms(1000); //Delay 1S 
   
        } 
}