#include <reg52.h>
#include "./delay/delay.h"
#include "./lcd/lcd.h"
#include "intrins.h"
#include "stdio.h"

sbit DS = P3^2;
sbit led = P3^3;

bit ack;

void ds18b20_init()
{
    DS = 0;
	delay_us(200);
	delay_us(200);
    DS = 1;
	delay_us(30);
	if(DS == 0)
	{
	   ack = 1;
	   led = 0;
	}
	else  ack = 0;
	delay_us(200);
}

void ds18b20_send_byte(unsigned char byte)
{
    unsigned char i;
    for(i=0;i<8;i++)
    {
        DS = 1;
        DS = 0;
        _nop_();
        _nop_();
        DS = byte && 0x01;
		byte = byte >> 1;
        delay_us(30); 
    }
	delay_us(30);
}

void ds18b20_write_byte(unsigned char byte)
{
    unsigned char i;
	for(i=0;i<8;i++)
	{
        DS = 1;
		DS = 0;
		_nop_();
		_nop_();
		DS = byte & 0x01;
		byte = byte >> 1;
		delay_us(30);
	}
	delay_us(30);
	DS = 1;
}

bit ds18b20_read_bit()
{
    bit tmp;
	DS = 1;
	DS = 0;
	_nop_();
	_nop_();
	DS = 1;
	tmp = DS;
	delay_us(30);
	return tmp;
}

unsigned char ds18b20_read_byte()
{
    unsigned char i,j,k=0;
	for(i=0;i<8;i++)
	{
	    j = ds18b20_read_bit();
		j = j << 7;
		k = k >> 1;
		k = j + k;
	}
	return k;
}

void main()
{
    float temp_f;
	unsigned char a;
    unsigned int temp,b;
	unsigned char disbuf[16];
	LCD_Init();
	LCD_Clear();
    //ds18b20_init();
    //ds18b20_send_byte(0x55);
	while(1)
	{
        ds18b20_init();
		ds18b20_write_byte(0xcc);
		ds18b20_write_byte(0x44);
		delay_ms(20);
		ds18b20_init();
		ds18b20_write_byte(0xcc);  
		ds18b20_write_byte(0xbe);
		a = ds18b20_read_byte();
		b = ds18b20_read_byte();
		temp = (b << 8) + a;
		temp_f = (float)temp * 0.0625;
		sprintf(disbuf,"temp is %7.3f",temp_f);
		LCD_Write_String(0,0,disbuf);
	}

}