7-Segment Interfacing With 8051 (AT89s52,LM35,ADC0804)

This time i show you to how to use 7 segment with AT89S52 and also interfacing of ADC0804 and temperature sensor with 8051.It is truly simple circuit .let gets started:

Component Required:

7 segment LED (4) common Anode

ADC0804.

Resistors 10K.

Temperature sensor LM35.

Micro-controller AT89S52.

Crystal Oscillator(11.0592MHz)

Transistor (BC558 or BC557)

Capacitor 22pf

ULN2803

WHY I AM USING COMMON ANODE LED:

In case of common anode LED internal pin of all LED of 7-segment are internally connected so it can directly connected to 5 volts.The output current provide by 8051 is too low to drive the LED directly. So a current driver ic can be used which is ULN2803. but if we common cathode LED all pins of 7-segment are directly connected to 8051 so it can not provide enough current to drive LED.

NOTE : For Common Anode LED BC557 or BC558 (PNP) transistors are used .

For Common cathode LED BC547 orBC548 (NPN) transistors are used.

All programming done in KEIL4.

Program for common anode LED:

#include <REGX51.h>

#define seg_data P0

sbit cs=P1^0;

sbit rd=P1^1;

sbit wr=P1^2;

sbit intr=P1^3;

sbit seg1=P1^4;

sbit seg2=P1^5;

sbit seg3=P1^6;

void delay();

void display_digit(int);

void main()

{

unsigned int Adcvalue,Adcvalue1,x;

char ch1,ch2,ch3;

seg1=seg2=seg3=1;

{

while(1)

{

cs=0;

rd=1;

wr=0;

wr=1;

if(intr==1)

{

cs=0;

rd=0;

Adcvalue=P2;

for(x=0;x<=100;x++){

if(Adcvalue>9){

ch1=Adcvalue/100;

display_digit(ch1);

P3=0xfe;

delay();

P3=0xff;

delay();

Adcvalue1=Adcvalue%100;

ch2=Adcvalue1/10;

display_digit(ch2);

P3=0xfd;

delay();

P3=0xff;delay();

ch3=Adcvalue1-(ch2*10);

display_digit(ch3);

P3=0xfb;

delay();

P3=0xff;

delay();

}

}

}

}

}

}

void display_digit(int c)

{

switch(c)

{ case 0: P0=0x3f;

break;

case 1: P0=0x06;

break;

case 2: P0=0x5b;

break;

case 3: P0=0x4f;

break;

case 4:P0=0x66;

break;

case 5: P0=0x6d;

break;

case 6:P0=0x7d;

break;

case 7:P0=0x07;

break;

case 8:P0=0x67;

break;

case 9:P0=0x40;

break;

return;

}

}

void delay()

{

unsigned int b;

for (b=0;b<=400;b++);

}

YOU CAN DOWNLOAD CODE FROM HERE :