18b20lcd.c

PIC16F877A单片机的C语言程序温度传感器DS18B20加1602液晶显示

#include<pic.h>
__CONFIG(0x3F3A);
# define DQ        RA4   //定义18B20数据端口     
# define DQ_DIR        TRISA4 //定义18B20D口方向寄存器 
# define W1_INPUT    1       
# define W1_OUTPUT    0       
# define FALSE        0 
# define TRUE        !FALSE 
# define DQ_HIGH()     DQ_DIR = W1_INPUT          
# define DQ_LOW()      DQ = 0; DQ_DIR = W1_OUTPUT 
# include <pic.h> 
# define uch unsigned char 
# define unint unsigned int 
unsigned int m=0;
char cc1[]="Temperature is :";
char cc2[]="+000.00 Degree";
//PIN define  
#define LCDRS RB3
#define LCDRW RB2
#define LCDE RB1
#define LCDDATA PORTD
///////////////////////////////

////////////////////////////////////
                    
 void delay_1us(void)                 //1us延时函数
  {
   asm("nop");
    asm("nop");
   
  }

void delay_nus(unsigned int n)       //N us延时函数
  {
   unsigned int i=0;
   for (i=0;i<n;i++)
   delay_1us();
  }
  
void delay_1ms(void)                 //1ms延时函数
  {
   unsigned int i;
   for (i=0;i<142;i++);
  }
  
void delay_nms(unsigned int n)       //N ms延时函数
  {
   unsigned int i=0;
   for (i=0;i<n;i++)
   delay_1ms();
  } 


void LCD_en_write(void)  //液晶使能
{
  LCDE=1;
  delay_nus(1);
  LCDE=0;
}

void LCD_write_command(unsigned char command) //写指令
{
  
  LCDRS=0;        //RS=0
  LCDDATA=command;//写低四位
  LCD_en_write();
  delay_nus(1);
}

void LCD_write_data(unsigned char data) //写数据
{

  LCDRS=1;      //RS=1
  LCDDATA=data;       //清高四位
  LCD_en_write();
  delay_nus(1);
}


void LCD_set_xy( unsigned char x, unsigned char y )  //写地址函数
{
    unsigned char address;
    if (y == 0) address = 0x80 + x;
    else   address = 0xc0 + x;
    LCD_write_command( address);
}
  
void LCD_write_string(unsigned char X,unsigned char Y,unsigned char *s) //列x=0~15,行y=0,1
{
    LCD_set_xy( X, Y ); //写地址    
    while (*s)  // 写显示字符
    {
      LCD_write_data( *s );
      s ++;
    }
      
}

void LCD_write_char(unsigned char X,unsigned char Y,unsigned char data) //列x=0~15,行y=0,1
{
  LCD_set_xy( X, Y ); //写地址
  LCD_write_data( data);
  
}
 void lcdinit() 
 
 
{TRISD=0x00;
 TRISB=0XF1;
 RB2=0;
 RD6=1;
 LCD_en_write();
 delay_nus(40);
 LCD_write_command(0x38);  //4位显示
 LCD_write_command(0x0c);  //显示开
 LCD_write_command(0x01);  //清屏
 delay_nms(2);
}




void delay(unint x)   
{ 
unint d; 
  d=x; 
while(--d) 
{;} 
} 
bit reset(void)                //初始化18B20 
{ 
    static bit presence;      //定义一个应答信号     
    DQ_LOW();  
     delay(70);                 //置总线为低电平并保持至少480us 
     
         
    DQ_HIGH();                //等电阻拉高总线并保持15－60us 

   // delay(5);
   while(DQ);     
    presence=DQ;              //接受应答信号 
   delay(20);                           //延时60－240us 
    
    return(presence);         //返回应答信号 
} 

//***************  读一位函数******************// 

bit read_bit(void)         
{ 
    static bit i; 

    DQ_LOW(); 
    DQ_LOW(); 
    DQ_HIGH(); 
   asm("nop"); 
   asm("nop"); 
   asm("nop"); 
    i=DQ; 

   delay(3); 
    return(i); 
} 

//*********************写一位函数****************// 

void write_bit(uch bitval)   
{     
    DQ_LOW(); 
   delay(1); 

    if (bitval==1)   
    { 
        DQ_HIGH(); 

    } 

     delay(3); 
    DQ_HIGH(); 
} 

//**************  从18B20中读一个字节**************// 

uch read_byte(void)        
{ 
    uch i; 
    uch j; 
    uch value=0; 
   
     
    for (i=0;i<8;i++) 
    { 
        j=read_bit();     //调读位函数 
       
        if (j)               //如果是 1 置1 
        { 
            value|=(0x01<<i);  //先读低位，再读高位 
           asm("nop"); 
           asm("nop"); 
           asm("nop"); 
        } 
    }                         //否则置 0 
    return(value);           
} 

//*********************向18B20中 写一个字节**************// 

void write_byte(uch val)     
{ 
    uch i; 
    uch temp; 
   
    
    for (i=0;i<8;i++) 
    { 
        temp=val>>i; 
        temp&=0x01; 
        write_bit(temp);   //调写位函数 
         
    } 
    asm("nop"); 
           asm("nop"); 
           asm("nop");      
}   
 unsigned int  read (void)
{ 
unsigned int temh,teml;
unsigned int value=0x550; 
         while (reset()) ;           //复位等待从机应答 
         write_byte(0XCC);         //忽略ROM匹配 
         write_byte(0X44);         //发送温度转化命令 
         
        
           delay(25000);   //延时100－300us 
        while( reset());          //再次复位，等待从机应答 
         write_byte(0XCC);          //忽略ROM匹配 
         write_byte(0XBE);          //发送读温度命令 
         teml =read_byte();          //读出温度低8        
         temh=read_byte();          //读出温度高8位 
         DQ_HIGH(); 
         value  =teml  ;    // 低字节 
         value += temh<<8;  // 高字节 
    
    return(value); 

    
    }
    
    void DS18B20_HEX_to_LCD(unsigned int x,char *p)
	{
	char temp;
	unsigned int temp2;
	char symbol='+';
	temp=(unsigned char)((x&0x07ff)>>4);
	if (x&0x800) symbol='-';
    p[0]=symbol;
	p[1]=temp/100+'0';
	
	p[2]=temp%100/10+'0';
	
	p[3]=temp%100%10+'0';
	if (p[1]=='0') {
		if (p[2]=='0') {p[2]=' ';}
		p[1]=' ';
		}
	temp2=(unsigned int)((x&0x000f)*625);
	p[5]=temp2/1000+'0';
	temp2=temp2%1000;
	p[6]=temp2/100+'0';
//	temp2=temp2%100;
//	p[7]=temp2/10+'0';
//	temp2=temp2%10;
//	p[8]=temp2+'0';
	
	}
 
void main()
{
 lcdinit();
 LCD_write_string(0,0,cc1);
 while(1)
		{   
		
			m=read();
			DS18B20_HEX_to_LCD(m,cc2);
			 delay_nus(50);
			LCD_write_string(0,1,cc2);
			 delay_nus(50);
 
 }
 }