main.c
#include <at89x52.h>
extern unsigned char digit1;
extern unsigned char digit2;
extern unsigned char digit3;
extern unsigned char digit4;
extern void timer_enable(void);
void main(void)
{
timer_enable();
while(1){
digit1=0x00;
digit2=0x01;
digit3=0x06;
digit4=0x03;
}
}
seven.c
#include <at89x52.h>
void display_digit(unsigned char);
#define dis_a P0_2
#define dis_b P0_3
#define dis_c P0_4
#define dis_d P0_6
#define dis_e P0_5
#define dis_f P0_1
#define dis_g P0_0
#define disp1 P2_7
#define disp2 P2_6
#define disp3 P2_5
#define disp4 P2_4
unsigned char count_val;
unsigned char digit1;
unsigned char digit2;
unsigned char digit3;
unsigned char digit4;
void timer_enable(void)
{
/*------------------------------------
Timer 0 routine for Display.
--------------------------------------*/
count_val=0x00; /*Clear Count value*/
TMOD = (TMOD & 0x0F) | 0x20; /* Set Mode (8-bit timer with reload) */
TH1 = 0x00; /* Reload TL1 to count 100 clocks */
TL1 = 0xff;
ET1 = 1; /* Enable Timer 1 Interrupts */
TR1 = 1; /* Start Timer 1 Running */
EA = 1; /* Global Interrupt Enable */
/*--------------------------------------*/
}
void timer1_ISR (void) interrupt 3
{
disp1=0;
disp2=0;
disp3=0;
disp4=0;
if (count_val==1){
disp1=1;
disp2=0;
disp3=0;
disp4=0;
display_digit(digit1);
}
else if (count_val==2){
disp1=0;
disp2=1;
disp3=0;
disp4=0;
display_digit(digit2);
}
else if (count_val==0x03){
disp1=0;
disp2=0;
disp3=1;
disp4=0;
display_digit(digit3);
}
else if (count_val==0x04){
disp1=0;
disp2=0;
disp3=0;
disp4=1;
display_digit(digit4);
count_val=0x00;
}
count_val++;
}
/*---------------------------------------------------
Display the data passed to this function
----------------------------------------------------*/
void display_digit(unsigned char digg)
{
if (digg==0x00)
{
dis_a=0;
dis_b=0;
dis_c=0;
dis_d=0;
dis_e=0;
dis_f=0;
dis_g=1;
}
else if (digg==1)
{
dis_a=1;
dis_b=0;
dis_c=0;
dis_d=1;
dis_e=1;
dis_f=1;
dis_g=1;
}
else if (digg==2)
{
dis_a=0;
dis_b=0;
dis_c=1;
dis_d=0;
dis_e=0;
dis_f=1;
dis_g=0;
}
else if (digg==3)
{
dis_a=0;
dis_b=0;
dis_c=0;
dis_d=0;
dis_e=1;
dis_f=1;
dis_g=0;
}
else if (digg==4)
{
dis_a=1;
dis_b=0;
dis_c=0;
dis_d=1;
dis_e=1;
dis_f=0;
dis_g=0;
}
else if (digg==5)
{
dis_a=0;
dis_b=1;
dis_c=0;
dis_d=0;
dis_e=1;
dis_f=0;
dis_g=0;
}
else if (digg==6)
{
dis_a=0;
dis_b=1;
dis_c=0;
dis_d=0;
dis_e=0;
dis_f=0;
dis_g=0;
}
else if (digg==7)
{
dis_a=0;
dis_b=0;
dis_c=0;
dis_d=1;
dis_e=1;
dis_f=1;
dis_g=1;
}
else if (digg==8)
{
dis_a=0;
dis_b=0;
dis_c=0;
dis_d=0;
dis_e=0;
dis_f=0;
dis_g=0;
}
else if (digg==9)
{
dis_a=0;
dis_b=0;
dis_c=0;
dis_d=0;
dis_e=1;
dis_f=0;
dis_g=0;
}
else if (digg==0x0A) /*For symbol -*/
{
dis_a=1;
dis_b=1;
dis_c=1;
dis_d=1;
dis_e=1;
dis_f=1;
dis_g=0;
}
}
