Seven Segment Display Interfacing With 8051 Primer

8051 HOW-TO GUIDE

Interfacing 7SEG with

8051

Join the Technical Community Today!

http://www.pantechsolutions.net

Contents at a Glance

8051 Primer Board ........................................................... 3

I2C (Inter Integrated Circuit) . Error! Bookmark not defined.

Seven Segment Display .................................................... 3

Interfacing Seven Segment Display .................................. 4

Interfacing Seven Segment with 8051 .............................. 5

Pin Assignment with 8051 ................................................ 6

Circuit Diagram to Interface 7 seg with 8051 .................... 7

Source Code .................................................................... 7

C Program to 7 Segment Display using 8051 ..................... 8



8051 Primer Board

The 8051 Primer board is specifically designed to help

students to master the required skills in the area of

embedded systems. The kit is designed in such way that all

the possible features of the microcontroller will be easily

used by the students. The kit supports in system

programming (ISP) which is done through serial port.

NXPs 8051 (AT89V51RD2), 8051 Primer Kit is proposed

to smooth the progress of developing and debugging of

various designs encompassing of speed 8-bit

Microcontrollers.

Seven Segment Display

A seven segment display is the most basic electronic

display device that can display digits from 0-9. The most

common configuration has an array of eight LEDs arranged

in a special pattern to display these digits. They are laid out

as a squared-off figure 8. Every LED is assigned a name



from 'a' to 'h' and is identified by its name. Seven LEDs 'a' to

'g' are used to display the numerals while eighth LED 'h' is

used to display the dot/decimal.

Interfacing I2C - Seven Segment Display

Fig. 1 shows how to interface the seven segments with

microcontroller. Seven segments are generally available in

ten pin package. While eight pins correspond to the eight

LEDs, the remaining two pins (at middle) are common and

internally shorted. These segments come in two

configurations, namely, Common cathode (CC) and

Common anode (CA). In CC configuration, the negative

terminals of all LEDs are connected to the common pins.

The common is connected to ground and a particular LED

glows when its corresponding pin is given high. In CA

arrangement, the common pin is given a high logic and the

LED pins are given low to display a number.



Fig. 1 Interfacing I2C - 7segment to Microcontroller

Interfacing Seven Segment with 8051

We now want to display a four digit number in 8051

Primer Board by using seven segment displays. The seven

segment display is connected with 801 controllers.

In 8051 Primer Kit, 4 nos. of common anode seven

segment displays are controlled I/O Lines(p1.0-p1.7).The 7-

segmend display is powered from the 5V power supply

enabled by switch SW30.



Pin Assignment with 8051

7-SEG 8051 Pins 7-Segment Display

Dig

it s

elec

t lin

es

Digit - 1 P3.4

Digit 2 P3.5

Digit 3 P3.6

Digit - 4 P3.7

Segm

en

t Li

ne

s

Seg - a P1.0

Seg b P1.1

Seg c P1.2

Seg d P1.3

Seg e P1.4

Seg f P1.5

Seg g P1.6

Seg dp P1.7

Make switch SW30 to

7SEG label marking position

+5V ON OFF

SW30

PWR ON/OFF

1 2 3 4

8 7 6 5

LCD 7SEG

GLCD SM/RL

Make high to - digit selection

Make low to - segment

f

a

b

c d e

g

VCC

1

2

3

1KDigit - 1

seg-aSeg-bSeg-cseg-d

seg-fseg-e

seg-gseg--dp

U1

7 SEG DISP

E1 D2

CA

3

C4

DP5

B6 A7

CA

8

F9

G10



Circuit Diagram to Interface 7 seg with 8051

Source Code

The Interfacing seven segment displays with 8051

program is very simple and straight forward that display a

four digit number in seven segment displays by using I/O

Lines. The C programs are developed in Keil software.



C Program to 7 Segment Display using 8051 ***************************************************************************************

Title : Program to I2C - Seven Segment display ***************************************************************************************

#include

#include

unsigned char SetDisplay(unsigned char);

void delay();

sbit eseg1000 = P3^7;

sbit eseg100 = P3^6;

sbit eseg10 = P3^5;

sbit eseg1 = P3^4;

unsigned char d0,d1,d2,d3;

unsigned char SetDisplay(unsigned char value)

{

unsigned char segment[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x83,0xf8,0x80,0x98};

if(value



}

//--------------

//Delay Function

//--------------

void delay()

{

int i;

for(i=0; i



{

eseg1000=0;

eseg100=0;

eseg10=0;

eseg1=1;

P1=SetDisplay(d0);

turn = 2;

delay();

}

else if(turn==2) //7-Seg Display 1

{

eseg1=0;

eseg1000=0;

eseg100=0;

eseg10=1;

P1=SetDisplay(d1);

turn = 3;

delay();

}

else if(turn==3) //7-Seg Display 2

{

eseg10=0;

eseg1=0;



eseg1000=0;

eseg100=1;

P1=SetDisplay(d2);

turn = 0;

delay();

}

else //7-Seg Display 3

{

eseg100=0;

eseg10=0;

eseg1=0;

eseg1000=1;

P1=SetDisplay(d3);

turn = 1;

delay();

}

if(timer == 100){

d0++;

timer=0;

if(d0>=10){

d0=0;

d1++;



if(d1>=10){

d1=0;

d2++;

if(d2>=10){

d2=0;

d3++;

if(d3>=10){

d3=0;

}

}

}

}

}

timer++;

}

}



Pantech solutions creates information packed technical

documents like this one every month. And our website is a rich

and trusted resource used by a vibrant online community of

more than 1,00,000 members from organization of all shapes

and sizes.

Did you enjoy the read?



What do we sell?

Our products range from Various Microcontroller

development boards, DSP Boards, FPGA/CPLD boards,

Communication Kits, Power electronics, Basic electronics,

Robotics, Sensors, Electronic components and much more . Our

goal is to make finding the parts and information you need

easier and affordable so you can create awesome projects and

training from Basic to Cutting edge technology.

Seven Segment Display Interfacing With 8051 Primer

Documents

segment display digit

segmend display

segment displays

common pins

common anode

common configuration

primer board

primer kit