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Embedded C code for Two 7 Segment displays


Sample code for Two 7 Segment displays using delay subroutine.
Following code can be using for AVR series ICs like: ATmega8, ATmega16, ATmega32. 

 

#include <avr/io.h>
#include <util/delay.h>

#define	DISPLAY_PORT	PORTD
#define	DISPLAY_DDR		DDRD

#define	DISPLAY_CTRL_PORT	PORTB
#define	DISPLAY_CTRL_DDR	DDRB

#define	ZERO       0x77 
#define	ONE        0x41
#define	TWO        0x3B
#define	THREE      0x6B
#define	FOUR       0x4D
#define	FIVE       0x6E
#define	SIX        0x7E
#define	SEVEN      0x43
#define	EIGHT      0x7F
#define	NINE       0x6F
#define	DOT        0x80

#define	DIGIT1				4	//(left most)
#define	DIGIT2				5
#define	DIGIT3				6
#define	DIGIT4				7	//(right most)


#ifndef cbi
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#endif

#ifndef sbi
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
#endif

int main(void)
{
	int i=0;
	int d1,d2,d3;
	
	DISPLAY_DDR=0xFF;
	DISPLAY_PORT=0x00;
	
	DISPLAY_CTRL_DDR=0xff;
	DISPLAY_CTRL_PORT=0x00;	
	
	_delay_ms(4000);
	
	while(1)
	{
	
	for(i=0;i<1000;i++)
	{
		sbi(DISPLAY_CTRL_PORT,DIGIT1);
		cbi(DISPLAY_CTRL_PORT,DIGIT2);
		cbi(DISPLAY_CTRL_PORT,DIGIT3);
		DISPLAY_PORT=d3;
		_delay_us(200);

		cbi(DISPLAY_CTRL_PORT,DIGIT1);
		sbi(DISPLAY_CTRL_PORT,DIGIT2);
		cbi(DISPLAY_CTRL_PORT,DIGIT3);
		DISPLAY_PORT=d2;
		_delay_us(200);
		
		cbi(DISPLAY_CTRL_PORT,DIGIT1);
		cbi(DISPLAY_CTRL_PORT,DIGIT2);
		sbi(DISPLAY_CTRL_PORT,DIGIT3);
		DISPLAY_PORT=d1;
		_delay_us(200);
	}
	
	for(i=0;i<1000;i++)
	{
		sbi(DISPLAY_CTRL_PORT,DIGIT1);
		cbi(DISPLAY_CTRL_PORT,DIGIT2);
		cbi(DISPLAY_CTRL_PORT,DIGIT3);
		DISPLAY_PORT=~SIX;
		_delay_us(200);

		cbi(DISPLAY_CTRL_PORT,DIGIT1);
		sbi(DISPLAY_CTRL_PORT,DIGIT2);
		cbi(DISPLAY_CTRL_PORT,DIGIT3);
		DISPLAY_PORT=~FIVE;
		_delay_us(200);
		
		cbi(DISPLAY_CTRL_PORT,DIGIT1);
		cbi(DISPLAY_CTRL_PORT,DIGIT2);
		sbi(DISPLAY_CTRL_PORT,DIGIT3);
		DISPLAY_PORT=~FOUR;
		_delay_us(200);
	}
	
	}	
	return 0;
}