Đo nhiệt độ ADC 0809+LM35+89C52 cần giúp đỡ?

[tiendat1242]

đã text ngon lành bác thử đoạn này xem sao ?

#include <REGX51.H>
#define START P3_0
#define ALE P3_1
#define A P3_2
#define B P3_3
#define C P3_4
#define dtlcd P2
#define adc P1

unsigned char code MA7D[10]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x90,0x8 0};
unsigned char nd;


void delay( unsigned int t)
{ while( t--); }

unsigned char docadc(unsigned char kenh)
{
A=kenh&(0x04);
B=kenh&(0x02);
C=kenh&(0x01);
START=ALE=1;
START=ALE=0;
delay(100);
return docadc;
}

void ht_nd()
{
nd=docadc(7);
delay(100);
P2=MA7D[nd/10]; P0_3=0; delay(100); P0_3=1;
P2=MA7D[nd%10]; P0_2=0; delay(100); P0_2=1;

}

void main()
{
while(1)
{ht_nd();
}
}

[dakvjp95]

có thể gửi cho mình nguyên lí này ko,trên này nhìn mờ quá :buiductu0@yahoo.com.vn

[hoangphuccdt]

mấy bạn giúp mình với!!!
mình viết code chạy mô phỏng thì ok nhưng sang mạch thực tế thì chỉ đọc được giá trị nhiệt độ ban đầu; khi nhiệt độ thay đổi thì nó ko đọc tiếp!!!!! giống như là adc nó đọc 1 lần thôi ko đọc lại; code mình để nó trong vòng lặp vô tận mà ko hiểu lí do sao lun; ai zúp mình với!!
code đây :
#include <REGX51.H>
#include <STDIO.H>
#include <math.h>
//#define VREF 5 //VREF=5V
#define ROLE P2_0
//Khai bao chan giao tiep ADC0808
#define ADC0808_DATA P3 //PORT
#define ADC0808_A P1_0 //PIN
#define ADC0808_B P1_1
#define ADC0808_C P1_2
#define ADC0808_ALE P1_5
#define ADC0808_START P1_3
#define ADC0808_EOC P1_4
#define ADC0808_OE P1_6
#define ADC0808_CLK P1_7
//Khai bao chan giao tiep LCD16x2 4bit
#define LCD_RS P0_0
#define LCD_RW P0_1
#define LCD_EN P0_2
#define LCD_D4 P0_4
#define LCD_D5 P0_5
#define LCD_D6 P0_6
#define LCD_D7 P0_7

/*****************ADC0808*********************/
//Ham doc ADC0808 theo kenh
unsigned char ADC0808_Read(unsigned char kenh){
unsigned char kq;

ADC0808_A = kenh & 0x01;
ADC0808_B = kenh & 0x02;
ADC0808_C = kenh & 0x04;

ADC0808_ALE = 1;
ADC0808_START = 1;
ADC0808_ALE = 0;
ADC0808_START = 0;

while(ADC0808_EOC);
while(!ADC0808_EOC);
ADC0808_OE = 1;
kq = ADC0808_DATA;
ADC0808_OE = 0;

return kq;
}
/*****************Ham delay*********************/
void delay_us(unsigned int t){
unsigned int i;
for(i=0;i<t;i++);
}
void delay_ms(unsigned int t){
unsigned int i,j;
for(i=0;i<t;i++)
for(j=0;j<125;j++);
}
/**************Ctr giao tiep LCD 16x2 4bit**********************/
void LCD_Enable(void){
LCD_EN =1;
delay_us(3);
LCD_EN=0;
delay_us(50);
}
//Ham Gui 4 Bit Du Lieu Ra LCD
void LCD_Send4Bit(unsigned char Data){
LCD_D4=Data & 0x01;
LCD_D5=(Data>>1)&1;
LCD_D6=(Data>>2)&1;
LCD_D7=(Data>>3)&1;
}
// Ham Gui 1 Lenh Cho LCD
void LCD_SendCommand(unsigned char command){
LCD_Send4Bit(command >>4);/* Gui 4 bit cao */
LCD_Enable();
LCD_Send4Bit(command); /* Gui 4 bit thap*/
LCD_Enable();
}
void LCD_Clear(){// Ham Xoa Man Hinh LCD
LCD_SendCommand(0x01);
delay_us(10);
}
// Ham Khoi Tao LCD
void LCD_Init(){
LCD_Send4Bit(0x00);
delay_ms(20);
LCD_RS=0;
LCD_RW=0;
LCD_Send4Bit(0x03);
LCD_Enable();
delay_ms(5);
LCD_Enable();
delay_us(100);
LCD_Enable();
LCD_Send4Bit(0x02);
LCD_Enable();
LCD_SendCommand( 0x28 ); // giao thuc 4 bit, hien thi 2 hang, ki tu 5x8
LCD_SendCommand( 0x0c); // cho phep hien thi man hinh
LCD_SendCommand( 0x06 ); // tang ID, khong dich khung hinh
LCD_SendCommand(0x01); // xoa toan bo khung hinh
}
void LCD_Gotoxy(unsigned char x, unsigned char y){
unsigned char address;
if(!y)address=(0x80+x);
else address=(0xc0+x);
delay_us(1000);
LCD_SendCommand(address);
delay_us(50);
}
void LCD_PutChar(unsigned char Data){//Ham Gui 1 Ki Tu
LCD_RS=1;
LCD_SendCommand(Data);
LCD_RS=0 ;
}
void LCD_Puts(char *s){//Ham gui 1 chuoi ky tu
while (*s){
LCD_PutChar(*s);
s++;
}
}
/**************Show Temp***********************
unsigned char Temp(unsigned char adc){//Tinh nhiet do tu adc8bit
return ((VREF*adc)/2.56f); //Tinh nhiet do
} */
void TempShow(unsigned char z){ //Chuyen doi hien thi
LCD_Puts("Nhiet do: ");
LCD_PutChar((z/100)+48);//Tram
LCD_PutChar((z%100/10)+48);//Chuc
LCD_PutChar((z%100%10/1)+48);//Don vi
LCD_Puts("'C");
}

/******************Ctr chinh**************************/
unsigned char temp,dv,ch,tr,gt=0,dem=0,t;
void main()
{

//Tao xung clock cho ADC0808 dung ngat timer
TMOD=0x02; //Timer0 8bit tu nap lai
TH0=TL0=226;//Tao ngat 20us
TR0=1;//Khoi dong timer0
ET0=1;//Ngat timer0
EA=1;//Cho phep ngat cuc bo
//init
LCD_Init();//Khoi tao LCD
delay_ms(200);
LCD_Puts("Do nhiet do...");//Gui chuoi len LCD
delay_ms(500);
LCD_Gotoxy(2,1);
LCD_Puts("Hoang Phuc");
delay_ms(500);
LCD_Clear();
while(1)
{

temp=ADC0808_Read(0); //Doc ADC0
LCD_Gotoxy(0,0);
//temp=Temp(temp); //Tinh nhiet do
TempShow(temp); //Hien thi nhiet do
LCD_Gotoxy(0,1);
LCD_Puts("NhietDoChuan:37'C ");
delay_ms(500);//0.5s doc mot lan
temp=0;
LCD_Clear();
LCD_Gotoxy(3,1);
LCD_Puts("HetVongLap");
delay_ms(500);
LCD_Clear();
// t= temp;
// if (t<=37)
// {
// ROLE=0;
// }
// else ROLE=1;
}
}
///******************Ctr ngat timer 0************/
void INT_Timer0()interrupt 1
{
//ctr phuc vu ngat tao xung clock cho ADC0808
ADC0808_CLK=~ADC0808_CLK; //Dao bit
}
//THE END