This project displays a clock over a 8x8 dot matrix display. The AT89S51 microcontroller is used and the software timer is used for the clock function.
You can also download the proteus simulation file of this project.
Circuit Diagram:
How to operate:
- The Mode button is used to change the clock to edit mode for changing the Hour & Minutes
- Press the Up botton to change the Hour/Minute
Program:
/*8x8 Dot matrix clock*/
#include <REGX51.H>
#include <intrins.h>
unsigned char timecount=0,oldP1=0xff,setting=0;
unsigned char sec=0,min=0,hou=12;
sbit SET=P2^2;
sbit UP=P2^4;
unsigned char code tab[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};
unsigned char code dis_code[40]={0x07c,0x082,0x082,0x07c,0x000,0x084,0x0fe,0x080, //0 and 1
0x0c4,0x0a2,0x092,0x08c,0x044,0x082,0x092,0x06c, //2 and 3
0x078,0x044,0x0fe,0x040,0x04e,0x08a,0x08a,0x072, //4 and 5
0x07c,0x092,0x092,0x064,0x006,0x002,0x0f2,0x00e, //6 and 7
0x06c,0x092,0x092,0x06c,0x04c,0x092,0x092,0x07c, //8 and 9
};
bit set_old;
bit up_old;
bit date_flag=1;
void time50ms(void);
void delay2ms(void);
void timedeal(void);
void main(void)
{
unsigned char offset=0,dis_p,scantimes=0;
unsigned char xian,disnum,x,y;
IE=0x82; //Enable interrupts
TMOD=0x01; //timer0 in mode 1
TR0=1; //start timer
TH0 = 0x3c;
TL0 = 0x0b;
do
{
if(setting==0){ //display clock
for(x=0;x<8;x++){
dis_p=x+offset;
if(dis_p>26)
dis_p-=27;
if(dis_p==0 || dis_p==5 || dis_p==10 || dis_p==12 || dis_p==17 || dis_p>21){ //row
y=0;
}else if(dis_p<=4){
xian=hou/10;
if(xian>0)
y=dis_code[xian*4+dis_p-1];
else
y=0;
}else if(dis_p<=9){
xian=hou%10;
y=dis_code[xian*4+dis_p-6];
}else if(dis_p==11){
if(date_flag)
y=0x24;
else
y=0;
}else if(dis_p<=16){
xian=min/10;
y=dis_code[xian*4+dis_p-13];
}else{
xian=min%10;
y=dis_code[xian*4+dis_p-18];
}
P0=0;
P1=tab[x];
P0=y;
delay2ms();
}
scantimes++;
if(scantimes>=8){
scantimes=0;
offset++;
if(offset>26)
offset=0;
}}
else{ //display time to change
for(x=0;x<8;x++)
{
if(setting==1)
disnum=min;
else
disnum=hou;
if(x<4)
{ xian=disnum/10;
y=dis_code[xian*4+x]; }
else
{
xian=disnum%10;
y=dis_code[xian*4+x-4];
}
P0=0;
P1=tab[x];
P0=y;
delay2ms();
}
}
}while(1);
}
void delay2ms(void)
{
unsigned char i,j;
for(i=0;i<4;i++)
for(j=0;j<120;j++);
}
void time50ms(void) interrupt 1
{
TH0 = 0x3c;
TL0 = 0x0b;
timecount++;
if(timecount==10)
{
timecount=0;
date_flag=!date_flag;
if(date_flag)
{
sec++;
timedeal();
}
}
if(!SET && SET!=set_old) //check the set key
{
setting++;
if(setting==3)
setting=0;
}
if(!UP && UP!=up_old) //check the up key
{
if(setting==1)
{
min++;
sec=0;
timedeal();
}else if(setting==2)
{
hou++;
timedeal();
}
}
set_old=SET;
up_old=UP;
}
void timedeal(void)
{
if(sec>=60)
{
sec=0;
min++;
}
if(min>=60)
{
min=0;
hou++;
}
if(hou>=24)
hou=0;
}
Download the code from here: 8x8-dot-matrix-clock.zip (30.72 kb)
Tags: 8x8 dot matrix display, clock, rtc, clock on matris display, 8051, c program