51 MCU 4-bit digital tube electronic clock source program

Title: Timer interrupt 24-hour clock program

Effect: Digital tube displays 24-hour clock (with time adjustment function)

Note: Use 12M crystal oscillator, key1=P3^7; key2=P3^6; key3=P3^5; key4=P3^4;

                  Digital tube position selection P1.0~P1.3, segment selection P0

*************************************************** ****************************/

 

#include

 

#define uchar unsigned char;

#define uint unsigned int;

                                              

 

uchar position;           

uchar tt;             

uchar second;       

uchar minute;

uchar hour;       

 

 

uchar code table[]=

                            {0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};//0--9

 

                  

sbit smg_q = P1^0; //digital tube thousands digit pin

sbit smg_b = P1^1;

sbit smg_s = P1^2;

sbit smg_g = P1^3;

 

sbit key1=P3^7; //button definition

sbit key2=P3^6;

sbit key3=P3^5;

sbit key4=P3^4;

 

 

void keyscan(); //Function declaration

void display(unsigned char hour, unsigned char minute);

void delay(unsigned int timer);

void init();                                              


/****************************************************** **********

                                     Main function

*************************************************** *********/

void main()

{

         init();                                    

         while(1)

         {

                   if(tt==20)

                   {                          

                            tt=0;

                            second++;

                            if(second==60)

                            {

                                     second=0;

                                     minute++;

                                     if(minute==60)

                                     {       

                                               minute=0;

                                               hour++;

                                               if(hour==24)

                                                        hour=0;

                                     }

                            }

                   }

 

                   keyscan();

                   display(hour,minute);      

                   delay(1);

         }

}

/****************************************************** **********

                                     Time Adjustment

*************************************************** *********/

void keyscan()

{

         if(key1==0) //hour plus 1

         {

                   TR0=0;

                   hour++;

                            if(hour==24)

                                     hour=0;

                   delay(200) ;

                   TR0=1;

         }

         if(key2==0) // hours minus

         {

                   TR0=0;

                   hour--;

                            if(hour<0)

                                     hour=23;

                   delay(200) ;

                   TR0=1;

         }

 

         if(key3==0) // add minutes

         {

                   TR0=0;

                   minute++;

                            if(minute==60)

                                     minute=0;

                   delay(200) ;

                   TR0=1;

         }

 

                   if(key4==0) // minutes minus

         {

                   TR0=0;

                   minute--;

                            if(minute<0)

                                     minute=59;

                   delay(200) ;

                   TR0=1;

         }

}

 

/****************************************************** **********

                                                initialization

*************************************************** *********/

void init()

{

         tt=0;

         position=0;               

         second=0;

         minute=0;        

         hour=0;   

         smg_q=1;

         smg_b=1;

         smg_s=1;

         smg_g=1;

         key1=1;

         key2=1;

 

         TMOD=0X01;  

         TH0=(65536-50000)/256;        

         TL0=(65536-50000)%256;

         EA=1;                

         ET0=1;              

         TR0=1;              

}

 

/****************************************************** **********

                                                  Timer TO interrupt

*************************************************** *********/

void t0() interrupt 1

{

         TH0=(65536-50000)/256;        

         TL0=(65536-50000)%256;

         tt++;                                              

}

 

/****************************************************** **********

                                          show

*************************************************** *********/

void display(unsigned char hour, unsigned char minute)

{

         P0=0XFF;                             

         switch(position)

         {

         case0:              

                   smg_g=1;

                   smg_q=0;

                   P0=table[hour/10];

                   break;

 

         case1:

                   smg_q=1;        

                   smg_b=0;        

                   P0=table[hour%10];

 

                   if(tt>=10)

                            P0&=0x7f; //The decimal point flashes for half a second

                   break;

 

         case2:    

                   smg_b=1;                  

                   smg_s=0;                  

                   P0=table[minute/10];

                   break;

         case3:                       

                   smg_s=1;

                   smg_g=0;

                   P0=table[minute%10];

                   break;

         }

         position++;               

         if(position>3)

                   position=0;      

}

 

/****************************************************** **********

                                                 Delay

*************************************************** *********/

void delay(unsigned int time)

{                

         unsignedint x,y;

         for(x=time;x>0;x--)

                   for(y=110;y>0;y--);

}