4-digits 7-Segment Display Interfacing with AVR microcontroller

  This code demonstrate How to interface 7-Segment display with AVR microcontroller. In this tutorial we are using 4-Digits of 7-Segment to display numbers, integer values, etc. 7-Segment display are commonly used for displaying voltage,current, temperature. This code is modular and simple to use customize or your application.

Components Required:

1. 7-Segment Display Qty-4

2. ATmega8 Microcontroller

3. BC548 Transistor Qty-4

4. 1KOhm Resistors

5. 330Ohm Resistors

Circuit Diagram:

AVR Studio C Code:

//=========================================================================
/*
 * 7 Segment Display With Decoder ATmega8 Interfacing
 *
 * Created: 02-02-2015 19:16:01
 *  Author: Komal Manoj Thakur
 */ 
//=========================================================================

#include <avr/io.h>
#include <avr/interrupt.h>
#include <string.h>
#define F_CPU 1000000UL
#include <util/delay.h>

#define Display_Port PORTB
#define Display_PortDir DDRB

int i, value;
char digit[4];
//=========================================================================
//   Main Function
//=========================================================================
int main(void)
{
 Display_PortDir=0xFF;
 
 TCCR0=0x04; //Set prescaling to 4, so Timer clock = Fosc/256
 TCNT0=0x91; //Timer 0 is 8-Bit Timer ADJUST TO REDUCE FLICKER
 TIMSK = 0x01; //Timer 0 Overflow flag interrupt enable
 sei();   //SREG= 0x80; Global Interrupt enable
  
 //digit[0]='5';  //Numbers to be displayed on display
 //digit[1]='6';
 //digit[2]='7';
 //digit[3]='8';
 
 value=1234;    //To display integer value on display
 sprintf(digit,"%04d",value);
 
    while(1)
    {
        //TODO:: Please write your application code 

  _delay_ms(1000);
    }
}


//=========================================================================
//                 Display Scanning Timer Interrupt
//=========================================================================
 SIGNAL(TIMER0_OVF_vect)
{
 i++;
 if(i==1)
 { Display_Port = (0x80 | (0x0F & digit[0])); }
 if(i==2)
 { Display_Port = (0x40 | (0x0F & digit[1])); }
 if(i==3)
 { Display_Port = (0x20 | (0x0F & digit[2])); }
 if(i==4)
 { Display_Port = (0x10 | (0x0F & digit[3])); i=0;}
 
 
 TCNT0=0x91;  //Reload the count ADJUST TO REDUCE FLICKER
}
//=========================================================================

Comment if you face any problem