DS18B20温度传感器的protues模拟 -

标题: DS18B20温度传感器的protues模拟 [打印本页]

作者: yx58yx58 时间: 2017-4-15 20:00
标题: DS18B20温度传感器的protues模拟
DS18B20温度传感器的protues模拟

#include<reg52.h>
#include<intrins.h>
#define uchar unsigned char
#define uint unsigned int

sbit wela = P2^0;
sbit dula = P2^1;
sbit IO_18B20 = P2^2;  //DS18B20通信引脚

uint temp;

uchar code table[]={0x3f,0x06,0x05b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};

void delay(uint ms) // ms延时函数 (AT89C51 @ 11.0592MHz)
{
      unsigned int i;
      unsigned char j;
      for(i=0;i<ms;i++)
      {
            for(j=0;j<200;j++);
            for(j=0;j<102;j++);
      }
}

/* 软件延时函数，延时时间(t*10)us */
void DelayX10us(unsigned char t)
{
do {
      _nop_();
      _nop_();
      _nop_();
      _nop_();
      _nop_();
      _nop_();
      _nop_();
      _nop_();
} while (--t);
}
bit Get18B20Ack()
{
      bit ack;

      EA = 0;
      IO_18B20 = 0;
      DelayX10us(50);
      IO_18B20 = 1;
      DelayX10us(6);
      ack = IO_18B20;
      while(!IO_18B20);
      DelayX10us(6);
      EA = 1;

      return ack;
}

void  Write18B20(unsigned char dat)
{
      unsigned char mask;
      EA = 0;
      for(mask=0x01; mask!= 0; mask<<=1)
      {
            IO_18B20 = 0;
            _nop_();
            _nop_();
            //_nop_();
            if((mask&dat) == 0)
                     IO_18B20 = 0;
            else
                     IO_18B20 = 1;
            DelayX10us(6);
            IO_18B20 = 1;
            _nop_();
            _nop_();
            _nop_();
      }
      EA = 1;
}

unsigned char Read18B20()
{
      unsigned char dat;
      unsigned char mask;

      EA = 0;
      for(mask=0x01; mask!=0; mask<<=1)
      {
            IO_18B20 = 0;
            _nop_();
            _nop_();
            //_nop_();
            IO_18B20 = 1;
            _nop_();
            _nop_();
            _nop_();
            if(!IO_18B20)
                     dat &= ~mask;
            else
                     dat |= mask;
            DelayX10us(6);
      }
      EA = 1;

      return dat;
}

bit Start18B20()
{
      bit ack;

      ack = Get18B20Ack();
      if(ack == 0)
      {
            Write18B20(0xCC);
            Write18B20(0x44);
      }
      return ~ack;
}

bit Get18B20Temp(uint *temp)
{
      bit ack;
      unsigned char LSB, MSB;

      ack = Get18B20Ack();
      if(ack == 0)
      {
            Write18B20(0xCC);
            Write18B20(0xBE);
            LSB = Read18B20();
            MSB = Read18B20();
            *temp = ((int)MSB<<8) + LSB;
      }
      return ~ack;
}

void display(uint num)
{
      uchar i;
      for(i=0;i<6;i++)
      {
            //位选
            P0 = ~(0x1<<i);
            wela = 1;
            wela = 0;
            //段选
            P0 = table[num%10];
            dula = 1;
      dula = 0;
            num=num/10;
            //去除前面为0的位
            if(num==0)
            {
                     i=6;
            }
            delay(3);
      }
}

void main()
{
      uint tmp;

      while(1)
      {
               if(Start18B20())
            {
                     if(Get18B20Temp(&temp))
                     {
                              tmp=temp;
                              tmp=tmp>>4;
                              tmp=tmp&0xFF;
                              display(tmp);
                     }
            }
      }
}

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