check the code,may the data is latching on the lcd.

Hi Keith,

Please post the code so that we can have a look

//Program to make a digital thermometer with display in centigrade scale

 

#include<reg51.h>

#define port P3

#define adc_input P1

#define dataport P0

#define sec 100

sbit rs = port^0;

sbit rw = port^1;

sbit e = port^2;

 

sbit wr= port^3;

sbit rd= port^4;

sbit intr= port^5;

 

int test_intermediate3=0, test_final=0,test_intermediate1[10],test_intermediate2[3]={0,0,0};

 

void delay(unsigned int msec )

{

int i ,j ;

for(i=0;i<msec;i++)

  for(j=0; j<1275; j++);

}

 

void lcd_cmd(unsigned char item)  //Function to send command to LCD

{

dataport = item;

rs= 0;

rw=0;

e=1;

delay(1);

e=0;

return;

}

 

void lcd_data(unsigned char item) //Function to send data to LCD

{

dataport = item;

rs= 1;

rw=0;

e=1;

delay(1);

e=0;

//delay(100);

return;

}

 

void lcd_data_string(unsigned char *str)  // Function to send string to LCD

{

int i=0;

while(str!=’’)

{

  lcd_data(str);

  i++;

  delay(10);

}

return;

}

 

void shape()     // Function to create the shape of degree

{

lcd_cmd(64);

lcd_data(2);

lcd_data(5);

lcd_data(2);

lcd_data(0);

lcd_data(0);

lcd_data(0);

lcd_data(0);

lcd_data(0);

}

    

void convert()    // Function to convert the values of ADC into numeric value to be sent to LCD

{

int s;

test_final=test_intermediate3;

lcd_cmd(0xc1);

delay(2);

lcd_data_string(“TEMP:”);

s=test_final/100;

test_final=test_final%100;

lcd_cmd(0xc8);

if(s!=0)

lcd_data(s+48);

else

lcd_cmd(0x06);

s=test_final/10;

test_final=test_final%10;

lcd_data(s+48);

lcd_data(test_final+48);

lcd_data(0);

lcd_data(‘c’);

lcd_data(‘ ‘);

delay(2);

}

 

void main()

{

int i,j;

adc_input=0xff;

lcd_cmd(0x38);

lcd_cmd(0x0c);  //Display On, Cursor  Blinking

delay(2);

lcd_cmd(0x01);  // Clear Screen

delay(2);

 

while(1)

{

  for(j=0;j<3;j++)

  {

   for(i=0;i<10;i++)

   {

    delay(1);

    rd=1;

    wr=0;

    delay(1);

    wr=1;

    while(intr==1);

    rd=0;

    lcd_cmd(0x88);

    test_intermediate1=adc_input/10;

    delay(1);

    intr=1;

   }

   for(i=0;i<10;i++)

   test_intermediate2[j]=test_intermediate1+test_intermediate2[j];

  }

 

test_intermediate2[0]=test_intermediate2[0]/3;

test_intermediate2[1]=test_intermediate2[1]/3;

test_intermediate2[2]=test_intermediate2[2]/3;

test_intermediate3=test_intermediate2[0]+test_intermediate2[1]+test_intermediate2[2];

shape();

convert();

}

}

Is your lcd displaying anything or just junk values only? Have you connected the reference pin of the adc? Is you circuit connection done for lcd 8 bit mode?

I got my circuit from this website, it says it is designed in 8 bit mode and I assume it is in 8 bit mode. It is displaying junk. My only concern is that im using the AT89C51AC2 training board and P1 or Port1 does not have 10k pull up resistors. P1 is the ADC input to the microcontroller and P0 is used as an output to the lcd. 

Please help us to locate the project by giving some hints like title, author or you could post a link of the same. If possible take a snapshot of the entire connection and lcd display seperate.

Hi my I got the code, circuit and everything from this website ! Look up celsius scale digital thermometer on the 8051 projects section on this website.

 

Thanks very much