Báo cháy sử dụng cảm biến DS18B20 và 8051 hiển thị LCD

**chung1608** · 12-03-2012, 16:05

Nguyên văn bởi Vinhanboy Xem bài viết

Phù phù... cuối cùng cũng sửa xong được cái code

Nhưng có một thắc mắc thế này, mong bác nào đã làm con này rồi giúp cho, khi nhiệt độ thay đổi thì hiển thị bên LCD thay đổi chậm hơn nhiều, sao vậy nhỉ ? Mong các bác tư vấn giúp

cái đó phụ thuộc thời gian lấy mẫu, xem bảng 2 trong datasheet để biết chi tiết

**Vinhanboy** · 13-03-2012, 18:06

Tình hình là đã xong được phần đo nhiệt độ của 4 con DS18b20, làm riêng nên viết code thật dài

. Nhưng bây giờ lại có theo một lỗi nữa, mà không biết tại làm sao. Trên LCD mình muốn hiển thị : Dòng 1 là số lượng xe , dòng 2 là nhiệt độ cao nhất . Nhưng mà khi chạy thì dòng 1 nó hiển thị sai ( ví dụ 50 thì nó hiển thị là y35) , trong khi dòng 2 vẫn hiển thị phần nhiệt độ đó được, mình ngắt kết nối với con DS18B20 ( trong hàm main vẫn gọi các lệnh đọc nhiệt độ bình thường ) thì dòng 1 lại hiển thị đúng. Các bác có cao kiến gì cho mình tham khảo với.

Code đây : Hơi dài, mong các bác thông cảm

Code:

#include<stdio.h>
#include<reg51.h>
sbit DQ  =  P2^0;
sbit DQ2 = P2^1;
sbit DQ3 = P2^2;
sbit DQ4 = P2^3;
char  readdata[2];
unsigned int t1,t2,t3,t4,nhietdo;
int xe= 50;
sbit xevao = P3^0;
sbit xera = P3^1;
	
// Khai bao cho LCD	--
sbit RS = P3^6;
sbit EN = P3^7; //RW=1 => doc
				//RS=0 => code
				//RS=1 => data
#define lcd_PORT P0

//===========================
void delay_ms1(int n)
{
	int k,j;
	for(k=0;k<n;k++)
	{
		for(j=0;j<500;j++);
	}


}
//==========================
void delay_5ms(){
int i,j;
for(i=0;i<250;i++)
for(j=0;j<4;j++){}
}
//===========================
void delay_15ms(){
int i,j;
for(i=0;i<250;i++)
for(j=0;j<100;j++){}
}
//============================
void lcd_command(unsigned char c) //CT con ghi du lieu len LCD
{
 RS=0;
 lcd_PORT=c;
 EN=1;
 EN=0;
 delay_5ms();
}
//==============================
void lcd_data(unsigned char c) //CT con doc du lieu tu LCD
{
 RS=1;
 lcd_PORT=c;
 EN=1;
 EN=0;
 delay_5ms();
}

//===============================
void lcd_init()  // Khoi tao LCD
{
	delay_15ms();
	lcd_command(0x38);
	lcd_command(0x0C);
	lcd_command(0x01);  // Xoa man hinh LCD
}

//=============================
void lcd_putsf(unsigned char *s)
{
 while (*s)
 {
  lcd_data(*s);
  s++;
 }
}

//------------------DS18b20---------------------------------------------------------------------
void DelayUs(int us)
{
	int i;
	for (i=0; i<us; i++);
}

//----------------------------------------
// Reset DS1820
//----------------------------------------
bit ResetDS1820(void)
{
	bit presence;
	DQ = 0; 		//pull DQ line low
	DelayUs(29); 	// leave it low for about 490us
	DQ = 1; 		// allow line to return high
	DelayUs(3); 	// wait for presence 55 uS
	presence = DQ; 	// get presence signal
	DelayUs(25); 	// wait for end of timeslot 316 uS 
	return(presence); // presence signal returned
} 	// 0=presence, 1 = no part

//-----------------------------------------
// Read one bit from DS1820
//-----------------------------------------
unsigned char ReadBit(void)
{
	unsigned char i;
	DQ = 0; 	// pull DQ low to start timeslot
	DQ=1;
	for (i=0; i<3; i++); // delay 17 us from start of timeslot
	return(DQ); // return value of DQ line
}

//-----------------------------------------
// Write one bit to DS1820
//-----------------------------------------
void WriteBit(char bitval)
{
	DQ=0;	
	if(bitval==1)
		DQ = 1;
	DelayUs(5); 			// delay about 39 uS
	DQ = 1;
}

//-----------------------------------------
// Read 1 byte from DS1820
//-----------------------------------------
unsigned char ReadByte(void)
{
	unsigned char i;
	unsigned char value = 0;
	for (i=0;i<8;i++)
	{
		if(ReadBit()) value|=0x01<<i;
		DelayUs(6); 
	}
	return(value);
}

//-----------------------------------------
// Write 1 byte
//-----------------------------------------
void WriteByte(char val)
{
	unsigned char i;
	unsigned char temp;

	for (i=0; i<8; i++) // writes byte, one bit at a time
	{	       
		temp = val>> i;
		temp &=0x01;
		WriteBit(temp);
	}
	DelayUs(5);
}

//-----------------------------------------
// Read temperature
//-----------------------------------------
void ReadTemp(void)
{
	int k;
	int thap, cao=0;
	ResetDS1820();
    WriteByte(0xcc);  // skip ROM
    WriteByte(0x44);  // perform temperatur conversion
    while (ReadByte()==0xff); // wait for conversion complete	
    ResetDS1820();
    WriteByte(0xcc);  // skip ROM
    WriteByte(0xbe);  // read the result
    for (k=0; k<9; k++)     // read 9 bytes but, use only one byte
    {
       readdata[k]=ReadByte();  // read DS1820
    } 
	thap = readdata[0];
	cao = readdata[1];
	readdata[1]=readdata[1]<<4; 
    readdata[1]=readdata[1] & 0x70; 
    thap=readdata[0]; 
    thap=thap>>4; 
    thap=thap & 0x0f; 
    readdata[1]=readdata[1] | thap; 
    thap=2; 
    t1=readdata[1];
}
// ---------------------------- DS18B20 --------> 2 ---------------------
bit ResetDS18202(void)
{
	bit presence;
	DQ2 = 0; 		//pull DQ line low
	DelayUs(29); 	// leave it low for about 490us
	DQ2 = 1; 		// allow line to return high
	DelayUs(3); 	// wait for presence 55 uS
	presence = DQ2; 	// get presence signal
	DelayUs(25); 	// wait for end of timeslot 316 uS 
	return(presence); // presence signal returned
} 	// 0=presence, 1 = no part

//-----------------------------------------
// Read one bit from DS1820
//-----------------------------------------
unsigned char ReadBit2(void)
{
	unsigned char i;
	DQ2 = 0; 	// pull DQ low to start timeslot
	DQ2 = 1;
	for (i=0; i<3; i++); // delay 17 us from start of timeslot
	return(DQ2); // return value of DQ line
}

//-----------------------------------------
// Write one bit to DS1820
//-----------------------------------------
void WriteBit2(char bitval)
{
	DQ2=0;	
	if(bitval==1)
		DQ2 = 1;
	DelayUs(5); 			// delay about 39 uS
	DQ2 = 1;
}

//-----------------------------------------
// Read 1 byte from DS1820
//-----------------------------------------
unsigned char ReadByte2(void)
{
	unsigned char i;
	unsigned char value = 0;
	for (i=0;i<8;i++)
	{
		if(ReadBit2()) value|=0x01<<i;
		DelayUs(6); 
	}
	return(value);
}

//-----------------------------------------
// Write 1 byte
//-----------------------------------------
void WriteByte2(char val)
{
	unsigned char i;
	unsigned char temp;

	for (i=0; i<8; i++) // writes byte, one bit at a time
	{	       
		temp = val>> i;
		temp &=0x01;
		WriteBit2(temp);
	}
	DelayUs(5);
}

//-----------------------------------------
// Read temperature
//-----------------------------------------
void ReadTemp2(void)
{
	int k;
	int thap, cao=0;	
	ResetDS18202();
    WriteByte2(0xcc);  // skip ROM
    WriteByte2(0x44);  // perform temperatur conversion
    while (ReadByte2()==0xff); // wait for conversion complete	
    ResetDS18202();
    WriteByte2(0xcc);  // skip ROM
    WriteByte2(0xbe);  // read the result
    for (k=0; k<9; k++)     // read 9 bytes but, use only one byte
    {
       readdata[k]=ReadByte2();  // read DS1820
    } 
	thap = readdata[0];
	cao = readdata[1];
	readdata[1]=readdata[1]<<4; 
    readdata[1]=readdata[1] & 0x70; 
    thap=readdata[0]; 
    thap=thap>>4; 
    thap=thap & 0x0f; 
    readdata[1]=readdata[1] | thap; 
    thap=2; 
    t2=readdata[1];
}

// ---------------------------- DS18B20 --------> 3 ---------------------
bit ResetDS18203(void)
{
	bit presence;
	DQ3 = 0; 		//pull DQ line low
	DelayUs(29); 	// leave it low for about 490us
	DQ3 = 1; 		// allow line to return high
	DelayUs(3); 	// wait for presence 55 uS
	presence = DQ3; 	// get presence signal
	DelayUs(25); 	// wait for end of timeslot 316 uS 
	return(presence); // presence signal returned
} 	// 0=presence, 1 = no part

//-----------------------------------------
// Read one bit from DS1820
//-----------------------------------------
unsigned char ReadBit3(void)
{
	unsigned char i;
	DQ3 = 0; 	// pull DQ low to start timeslot
	DQ3 = 1;
	for (i=0; i<3; i++); // delay 17 us from start of timeslot
	return(DQ3); // return value of DQ line
}

//-----------------------------------------
// Write one bit to DS1820
//-----------------------------------------
void WriteBit3(char bitval)
{
	DQ3=0;	
	if(bitval==1)
		DQ3 = 1;
	DelayUs(5); 			// delay about 39 uS
	DQ3 = 1;
}

//-----------------------------------------
// Read 1 byte from DS1820
//-----------------------------------------
unsigned char ReadByte3(void)
{
	unsigned char i;
	unsigned char value = 0;
	for (i=0;i<8;i++)
	{
		if(ReadBit3()) value|=0x01<<i;
		DelayUs(6); 
	}
	return(value);
}

//-----------------------------------------
// Write 1 byte
//-----------------------------------------
void WriteByte3(char val)
{
	unsigned char i;
	unsigned char temp;

	for (i=0; i<8; i++) // writes byte, one bit at a time
	{	       
		temp = val>> i;
		temp &=0x01;
		WriteBit3(temp);
	}
	DelayUs(5);
}

//-----------------------------------------
// Read temperature
//-----------------------------------------
void ReadTemp3(void)
{
	int k;
	int thap, cao=0;	
	ResetDS18203();
    WriteByte3(0xcc);  // skip ROM
    WriteByte3(0x44);  // perform temperatur conversion
    while (ReadByte3()==0xff); // wait for conversion complete	
    ResetDS18203();
    WriteByte3(0xcc);  // skip ROM
    WriteByte3(0xbe);  // read the result
    for (k=0; k<9; k++)     // read 9 bytes but, use only one byte
    {
       readdata[k]=ReadByte3();  // read DS1820
    } 
	thap = readdata[0];
	cao = readdata[1];
	readdata[1]=readdata[1]<<4; 
    readdata[1]=readdata[1] & 0x70; 
    thap=readdata[0]; 
    thap=thap>>4; 
    thap=thap & 0x0f; 
    readdata[1]=readdata[1] | thap; 
    thap=2; 
    t3=readdata[1];
}
// ---------------------------- DS18B20 --------> 4 ---------------------
bit ResetDS18204(void)
{
	bit presence;
	DQ4 = 0; 		//pull DQ line low
	DelayUs(29); 	// leave it low for about 490us
	DQ4 = 1; 		// allow line to return high
	DelayUs(3); 	// wait for presence 55 uS
	presence = DQ4; 	// get presence signal
	DelayUs(25); 	// wait for end of timeslot 316 uS 
	return(presence); // presence signal returned
} 	// 0=presence, 1 = no part

//-----------------------------------------
// Read one bit from DS1820
//-----------------------------------------
unsigned char ReadBit4(void)
{
	unsigned char i;
	DQ4 = 0; 	// pull DQ low to start timeslot
	DQ4 = 1;
	for (i=0; i<3; i++); // delay 17 us from start of timeslot
	return(DQ4); // return value of DQ line
}

//-----------------------------------------
// Write one bit to DS1820
//-----------------------------------------
void WriteBit4(char bitval)
{
	DQ4=0;	
	if(bitval==1)
		DQ4 = 1;
	DelayUs(5); 			// delay about 39 uS
	DQ4 = 1;
}

//-----------------------------------------
// Read 1 byte from DS1820
//-----------------------------------------
unsigned char ReadByte4(void)
{
	unsigned char i;
	unsigned char value = 0;
	for (i=0;i<8;i++)
	{
		if(ReadBit4()) value|=0x01<<i;
		DelayUs(6); 
	}
	return(value);
}

//-----------------------------------------
// Write 1 byte
//-----------------------------------------
void WriteByte4(char val)
{
	unsigned char i;
	unsigned char temp;

	for (i=0; i<8; i++) // writes byte, one bit at a time
	{	       
		temp = val>> i;
		temp &=0x01;
		WriteBit4(temp);
	}
	DelayUs(5);
}

//-----------------------------------------
// Read temperature
//-----------------------------------------
void ReadTemp4(void)
{
	int k;
	int thap, cao=0;	
	ResetDS18204();
    WriteByte4(0xcc);  // skip ROM
    WriteByte4(0x44);  // perform temperatur conversion
    while (ReadByte4()==0xff); // wait for conversion complete	
    ResetDS18204();
    WriteByte4(0xcc);  // skip ROM
    WriteByte4(0xbe);  // read the result
    for (k=0; k<9; k++)     // read 9 bytes but, use only one byte
    {
       readdata[k]=ReadByte4();  // read DS1820
    } 
	thap = readdata[0];
	cao = readdata[1];
	readdata[1]=readdata[1]<<4; 
    readdata[1]=readdata[1] & 0x70; 
    thap=readdata[0]; 
    thap=thap>>4; 
    thap=thap & 0x0f; 
    readdata[1]=readdata[1] | thap; 
    thap=2; 
    t4=readdata[1];
}

//-------------- Ham hien thi nhiet do
void HienThi_ADC(unsigned char so)
{
	
	if ( so<100)
	{
	//lcd_data(t/100+48);
	lcd_data(((so/10)%10)+48);
	lcd_data(so%10+48);
	}
	else
	{
	lcd_data(so/100+48);
	lcd_data(((so/10)%10)+48);
	lcd_data(so%10+48);
	}
}
void Hienthiso(unsigned int count)
{
	
 	lcd_data(count/100+48);
	lcd_data(((count/10)%10)+48);
	lcd_data(count%10+48);
}
//--------------------------------------------
void main (void)
{
   	lcd_init();

	IE=0XAF;
	IT0=1;
	lcd_command(0x01);
    lcd_command(0x80);
	lcd_putsf("Welcome");
	lcd_command(0xC0);
	lcd_putsf("Bai giu xe O");
	delay_ms1(100);
   	while(1)
	{
		      	
		lcd_command(0x80);
		lcd_putsf("So luong xe: ");
		Hienthiso(xe);
		lcd_command(0xC0);
		lcd_putsf("Nhiet do: ");
		ReadTemp();
		ReadTemp2();
		ReadTemp3();
		ReadTemp4();
		nhietdo = t1;
		if(nhietdo < t2 )
			nhietdo = t2;
		if(nhietdo < t3)
			nhietdo = t3;
		if(nhietdo < t4 )
			nhietdo = t4;
		HienThi_ADC(nhietdo);

	  	lcd_command(0xc0+14);          
      	lcd_putsf("oC ");	    
		delay_ms1(10);

	}
}
void ngat0(void) interrupt 0
{
	EA=0;
	xe++;
	//if(x==100)x=0;
	delay_ms1(100);
	EA=1;
}
void ngat1(void) interrupt 2
{
	EA=0;
	xe--;
	//if(x==100)x=0;
	delay_ms1(100);
	EA=1;
}

**Vinhanboy** · 21-03-2012, 12:55

Code:

#include<stdio.h>
#include<reg51.h>
sbit DQ  =  P2^0;
sbit DQ2 = P2^1;
sbit DQ3 = P2^2;
sbit DQ4 = P2^3;
char  readdata[2];
unsigned int t1,t2,t3,t4,nhietdo;
int xe= 50;
sbit xevao = P3^0;
sbit xera = P3^1;
	
// Khai bao cho LCD	--
sbit RS = P3^6;
sbit EN = P3^7; //RW=1 => doc
				//RS=0 => code
				//RS=1 => data
#define lcd_PORT P0

//===========================
void delay_ms1(int n)
{
	int k,j;
	for(k=0;k<n;k++)
	{
		for(j=0;j<500;j++);
	}


}
//==========================
void delay_5ms(){
int i,j;
for(i=0;i<250;i++)
for(j=0;j<4;j++){}
}
//===========================
void delay_15ms(){
int i,j;
for(i=0;i<250;i++)
for(j=0;j<100;j++){}
}
//============================
void lcd_command(unsigned char c) //CT con ghi du lieu len LCD
{
 RS=0;
 lcd_PORT=c;
 EN=1;
 EN=0;
 delay_5ms();
}
//==============================
void lcd_data(unsigned char c) //CT con doc du lieu tu LCD
{
 RS=1;
 lcd_PORT=c;
 EN=1;
 EN=0;
 delay_5ms();
}

//===============================
void lcd_init()  // Khoi tao LCD
{
	delay_15ms();
	lcd_command(0x38);
	lcd_command(0x0C);
	lcd_command(0x01);  // Xoa man hinh LCD
}

//=============================
void lcd_putsf(unsigned char *s)
{
 while (*s)
 {
  lcd_data(*s);
  s++;
 }
}

//------------------DS18b20---------------------------------------------------------------------
void DelayUs(int us)
{
	int i;
	for (i=0; i<us; i++);
}

//----------------------------------------
// Reset DS1820
//----------------------------------------
bit ResetDS1820(void)
{
	bit presence;
	DQ = 0; 		//pull DQ line low
	DelayUs(29); 	// leave it low for about 490us
	DQ = 1; 		// allow line to return high
	DelayUs(3); 	// wait for presence 55 uS
	presence = DQ; 	// get presence signal
	DelayUs(25); 	// wait for end of timeslot 316 uS 
	return(presence); // presence signal returned
} 	// 0=presence, 1 = no part

//-----------------------------------------
// Read one bit from DS1820
//-----------------------------------------
unsigned char ReadBit(void)
{
	unsigned char i;
	DQ = 0; 	// pull DQ low to start timeslot
	DQ=1;
	for (i=0; i<3; i++); // delay 17 us from start of timeslot
	return(DQ); // return value of DQ line
}

//-----------------------------------------
// Write one bit to DS1820
//-----------------------------------------
void WriteBit(char bitval)
{
	DQ=0;	
	if(bitval==1)
		DQ = 1;
	DelayUs(5); 			// delay about 39 uS
	DQ = 1;
}

//-----------------------------------------
// Read 1 byte from DS1820
//-----------------------------------------
unsigned char ReadByte(void)
{
	unsigned char i;
	unsigned char value = 0;
	for (i=0;i<8;i++)
	{
		if(ReadBit()) value|=0x01<<i;
		DelayUs(6); 
	}
	return(value);
}

//-----------------------------------------
// Write 1 byte
//-----------------------------------------
void WriteByte(char val)
{
	unsigned char i;
	unsigned char temp;

	for (i=0; i<8; i++) // writes byte, one bit at a time
	{	       
		temp = val>> i;
		temp &=0x01;
		WriteBit(temp);
	}
	DelayUs(5);
}

//-----------------------------------------
// Read temperature
//-----------------------------------------
void ReadTemp(void)
{
	int k;
	int thap, cao=0;
	ResetDS1820();
    WriteByte(0xcc);  // skip ROM
    WriteByte(0x44);  // perform temperatur conversion
    while (ReadByte()==0xff); // wait for conversion complete	
    ResetDS1820();
    WriteByte(0xcc);  // skip ROM
    WriteByte(0xbe);  // read the result
    for (k=0; k<9; k++)     // read 9 bytes but, use only one byte
    {
       readdata[k]=ReadByte();  // read DS1820
    } 
	thap = readdata[0];
	cao = readdata[1];
	readdata[1]=readdata[1]<<4; 
    readdata[1]=readdata[1] & 0x70; 
    thap=readdata[0]; 
    thap=thap>>4; 
    thap=thap & 0x0f; 
    readdata[1]=readdata[1] | thap; 
    thap=2; 
    t1=readdata[1];
}
// ---------------------------- DS18B20 --------> 2 ---------------------
bit ResetDS18202(void)
{
	bit presence;
	DQ2 = 0; 		//pull DQ line low
	DelayUs(29); 	// leave it low for about 490us
	DQ2 = 1; 		// allow line to return high
	DelayUs(3); 	// wait for presence 55 uS
	presence = DQ2; 	// get presence signal
	DelayUs(25); 	// wait for end of timeslot 316 uS 
	return(presence); // presence signal returned
} 	// 0=presence, 1 = no part

//-----------------------------------------
// Read one bit from DS1820
//-----------------------------------------
unsigned char ReadBit2(void)
{
	unsigned char i;
	DQ2 = 0; 	// pull DQ low to start timeslot
	DQ2 = 1;
	for (i=0; i<3; i++); // delay 17 us from start of timeslot
	return(DQ2); // return value of DQ line
}

//-----------------------------------------
// Write one bit to DS1820
//-----------------------------------------
void WriteBit2(char bitval)
{
	DQ2=0;	
	if(bitval==1)
		DQ2 = 1;
	DelayUs(5); 			// delay about 39 uS
	DQ2 = 1;
}

//-----------------------------------------
// Read 1 byte from DS1820
//-----------------------------------------
unsigned char ReadByte2(void)
{
	unsigned char i;
	unsigned char value = 0;
	for (i=0;i<8;i++)
	{
		if(ReadBit2()) value|=0x01<<i;
		DelayUs(6); 
	}
	return(value);
}

//-----------------------------------------
// Write 1 byte
//-----------------------------------------
void WriteByte2(char val)
{
	unsigned char i;
	unsigned char temp;

	for (i=0; i<8; i++) // writes byte, one bit at a time
	{	       
		temp = val>> i;
		temp &=0x01;
		WriteBit2(temp);
	}
	DelayUs(5);
}

//-----------------------------------------
// Read temperature
//-----------------------------------------
void ReadTemp2(void)
{
	int k;
	int thap, cao=0;	
	ResetDS18202();
    WriteByte2(0xcc);  // skip ROM
    WriteByte2(0x44);  // perform temperatur conversion
    while (ReadByte2()==0xff); // wait for conversion complete	
    ResetDS18202();
    WriteByte2(0xcc);  // skip ROM
    WriteByte2(0xbe);  // read the result
    for (k=0; k<9; k++)     // read 9 bytes but, use only one byte
    {
       readdata[k]=ReadByte2();  // read DS1820
    } 
	thap = readdata[0];
	cao = readdata[1];
	readdata[1]=readdata[1]<<4; 
    readdata[1]=readdata[1] & 0x70; 
    thap=readdata[0]; 
    thap=thap>>4; 
    thap=thap & 0x0f; 
    readdata[1]=readdata[1] | thap; 
    thap=2; 
    t2=readdata[1];
}

// ---------------------------- DS18B20 --------> 3 ---------------------
bit ResetDS18203(void)
{
	bit presence;
	DQ3 = 0; 		//pull DQ line low
	DelayUs(29); 	// leave it low for about 490us
	DQ3 = 1; 		// allow line to return high
	DelayUs(3); 	// wait for presence 55 uS
	presence = DQ3; 	// get presence signal
	DelayUs(25); 	// wait for end of timeslot 316 uS 
	return(presence); // presence signal returned
} 	// 0=presence, 1 = no part

//-----------------------------------------
// Read one bit from DS1820
//-----------------------------------------
unsigned char ReadBit3(void)
{
	unsigned char i;
	DQ3 = 0; 	// pull DQ low to start timeslot
	DQ3 = 1;
	for (i=0; i<3; i++); // delay 17 us from start of timeslot
	return(DQ3); // return value of DQ line
}

//-----------------------------------------
// Write one bit to DS1820
//-----------------------------------------
void WriteBit3(char bitval)
{
	DQ3=0;	
	if(bitval==1)
		DQ3 = 1;
	DelayUs(5); 			// delay about 39 uS
	DQ3 = 1;
}

//-----------------------------------------
// Read 1 byte from DS1820
//-----------------------------------------
unsigned char ReadByte3(void)
{
	unsigned char i;
	unsigned char value = 0;
	for (i=0;i<8;i++)
	{
		if(ReadBit3()) value|=0x01<<i;
		DelayUs(6); 
	}
	return(value);
}

//-----------------------------------------
// Write 1 byte
//-----------------------------------------
void WriteByte3(char val)
{
	unsigned char i;
	unsigned char temp;

	for (i=0; i<8; i++) // writes byte, one bit at a time
	{	       
		temp = val>> i;
		temp &=0x01;
		WriteBit3(temp);
	}
	DelayUs(5);
}

//-----------------------------------------
// Read temperature
//-----------------------------------------
void ReadTemp3(void)
{
	int k;
	int thap, cao=0;	
	ResetDS18203();
    WriteByte3(0xcc);  // skip ROM
    WriteByte3(0x44);  // perform temperatur conversion
    while (ReadByte3()==0xff); // wait for conversion complete	
    ResetDS18203();
    WriteByte3(0xcc);  // skip ROM
    WriteByte3(0xbe);  // read the result
    for (k=0; k<9; k++)     // read 9 bytes but, use only one byte
    {
       readdata[k]=ReadByte3();  // read DS1820
    } 
	thap = readdata[0];
	cao = readdata[1];
	readdata[1]=readdata[1]<<4; 
    readdata[1]=readdata[1] & 0x70; 
    thap=readdata[0]; 
    thap=thap>>4; 
    thap=thap & 0x0f; 
    readdata[1]=readdata[1] | thap; 
    thap=2; 
    t3=readdata[1];
}
// ---------------------------- DS18B20 --------> 4 ---------------------
bit ResetDS18204(void)
{
	bit presence;
	DQ4 = 0; 		//pull DQ line low
	DelayUs(29); 	// leave it low for about 490us
	DQ4 = 1; 		// allow line to return high
	DelayUs(3); 	// wait for presence 55 uS
	presence = DQ4; 	// get presence signal
	DelayUs(25); 	// wait for end of timeslot 316 uS 
	return(presence); // presence signal returned
} 	// 0=presence, 1 = no part

//-----------------------------------------
// Read one bit from DS1820
//-----------------------------------------
unsigned char ReadBit4(void)
{
	unsigned char i;
	DQ4 = 0; 	// pull DQ low to start timeslot
	DQ4 = 1;
	for (i=0; i<3; i++); // delay 17 us from start of timeslot
	return(DQ4); // return value of DQ line
}

//-----------------------------------------
// Write one bit to DS1820
//-----------------------------------------
void WriteBit4(char bitval)
{
	DQ4=0;	
	if(bitval==1)
		DQ4 = 1;
	DelayUs(5); 			// delay about 39 uS
	DQ4 = 1;
}

//-----------------------------------------
// Read 1 byte from DS1820
//-----------------------------------------
unsigned char ReadByte4(void)
{
	unsigned char i;
	unsigned char value = 0;
	for (i=0;i<8;i++)
	{
		if(ReadBit4()) value|=0x01<<i;
		DelayUs(6); 
	}
	return(value);
}

//-----------------------------------------
// Write 1 byte
//-----------------------------------------
void WriteByte4(char val)
{
	unsigned char i;
	unsigned char temp;

	for (i=0; i<8; i++) // writes byte, one bit at a time
	{	       
		temp = val>> i;
		temp &=0x01;
		WriteBit4(temp);
	}
	DelayUs(5);
}

//-----------------------------------------
// Read temperature
//-----------------------------------------
void ReadTemp4(void)
{
	int k;
	int thap, cao=0;	
	ResetDS18204();
    WriteByte4(0xcc);  // skip ROM
    WriteByte4(0x44);  // perform temperatur conversion
    while (ReadByte4()==0xff); // wait for conversion complete	
    ResetDS18204();
    WriteByte4(0xcc);  // skip ROM
    WriteByte4(0xbe);  // read the result
    for (k=0; k<9; k++)     // read 9 bytes but, use only one byte
    {
       readdata[k]=ReadByte4();  // read DS1820
    } 
	thap = readdata[0];
	cao = readdata[1];
	readdata[1]=readdata[1]<<4; 
    readdata[1]=readdata[1] & 0x70; 
    thap=readdata[0]; 
    thap=thap>>4; 
    thap=thap & 0x0f; 
    readdata[1]=readdata[1] | thap; 
    thap=2; 
    t4=readdata[1];
}

//-------------- Ham hien thi nhiet do
void HienThi_ADC(unsigned char so)
{
	
	if ( so<100)
	{
	//lcd_data(t/100+48);
	lcd_data(((so/10)%10)+48);
	lcd_data(so%10+48);
	}
	else
	{
	lcd_data(so/100+48);
	lcd_data(((so/10)%10)+48);
	lcd_data(so%10+48);
	}
}
void Hienthiso(unsigned int count)
{
	
 	lcd_data(count/100+48);
	lcd_data(((count/10)%10)+48);
	lcd_data(count%10+48);
}
//--------------------------------------------
void main (void)
{
   	lcd_init();

	IE=0XAF;
	IT0=1;
	lcd_command(0x01);
    lcd_command(0x80);
	lcd_putsf("Welcome");
	lcd_command(0xC0);
	lcd_putsf("Bai giu xe O");
	delay_ms1(100);
   	while(1)
	{
		      	
		lcd_command(0x80);
		lcd_putsf("So luong xe: ");
		Hienthiso(xe);
		lcd_command(0xC0);
		lcd_putsf("Nhiet do: ");
		ReadTemp();
		ReadTemp2();
		ReadTemp3();
		ReadTemp4();
		nhietdo = t1;
		if(nhietdo < t2 )
			nhietdo = t2;
		if(nhietdo < t3)
			nhietdo = t3;
		if(nhietdo < t4 )
			nhietdo = t4;
		HienThi_ADC(nhietdo);

	  	lcd_command(0xc0+14);          
      	lcd_putsf("oC ");	    
		delay_ms1(10);

	}
}
void ngat0(void) interrupt 0
{
	EA=0;
	xe++;
	//if(x==100)x=0;
	delay_ms1(100);
	EA=1;
}
void ngat1(void) interrupt 2
{
	EA=0;
	xe--;
	//if(x==100)x=0;
	delay_ms1(100);
	EA=1;
}

Mình đã chạy mô phỏng code này trên Protues thành công, nhưng không hiểu sao khi nạp vào VĐK lại chạy bị lỗi. Không phải ko chạy được, nhưng nó chỉ chạy được 1 phần thôi. Rồi đứng luôn... cái này lỗi do VĐK phải ko? Nhưng con VĐK này mình nạp ct khác thì vẫn chạy bt )

Các cao thủ giúp với.

**soccon_yeu** · 02-12-2012, 16:13

đồ án ngon chưa cậu,cho mình xin file về hc tập đc không

Báo cháy sử dụng cảm biến DS18B20 và 8051 hiển thị LCD

Comment

Comment

Comment

Comment

Về tác giả

Bài viết mới nhất