/*   CLOCK V1.0   89C2051 + 4-digit 7-SEG led + 4-key switch   Simple Digital Clock demostrates scanning LED and key switch.   The clock has 1-bit output port P3.7 for driving AC load through MOC3040+triac.      The source program was modified for Proview32 C51 Compiler.   3 November 2542           *    ****       ****    ****           *   *    *  *  *    *  *    *           *   *    *     *    *  *    *           *    ****      *    *  *    *           *   *    *     *    *  *    *           *   *    *  *  *    *  *    *           *    ****       ****    ****              set   set  time    manual             HOUR   MIN  ON/OFF  ON/OFF   Copyright (c) 1999 W.SIRICHOTE*/#include <reg52.h>               /* special function register declarations   */                                  /* for the AT89C52       */#include <stdio.h>      unsigned  char sec100,sec,sec5,min,hour,flag1,command,temp,opto;/* above must be defined as register for tiny model */unsigned char i,digit,buffer[4],onHour1,onMin1,offHour1,offMin1;char cputick,key,delay,count1;char convert[10] = {0x3F,0x0c,0x76,0x5e,0x4d,0x5b,0x7b,0x0e,0x7f,0x5f};void pause(int); void scanLED();void manualOnOff();void savetimeOnOff1(); void setmin();void sethour();void showOnce();void savetimeOff1();void time();void timeToBuffer();void blink();void offmsd();void keyexe();void keydelay();void comparetime();void timer0int (void)  interrupt 1  using 1  {	TH0 |= 0xdc;  // reload timer 0 with 0DC00H	cputick++;	time();       // update realtime clock           }void main(){  EA = 1;  ET0 = 1;  // or IE |= 0x82;   /* set bit EA and Timer0 enable */   TMOD |= 0x01; /* timer 0 run 16 bit counter */  TR0 = 1; //or TCON |= 0x10; /* run timer 0 */  opto = 0xff;  cputick = 0;  hour = 18;  min = 0;  sec = 0;  key = -1;  flag1 = 0;  onHour1 = 18;   /* 18:30 turn lamp on */  onMin1 = 01;  offHour1 = 18;   /* 21:30 turn off */  offMin1 = 02;  count1 = 0;  buffer[0] = 0x40;  buffer[1] = 0x40;  buffer[2] = 0x40;  buffer[3] = 0x40; // serinit(9600);     /* must be invoked for tiny model */  while(1)  {    while ( cputick < 1)    scanLED();    cputick = 0;/*------------- the following tasks execute every 10ms ------*/   // time();    timeToBuffer();    blink();    offmsd();    keyexe();    keydelay();    comparetime();/*-----------------------------------------------------------*/   }}/* ****************** change constant below for other X-tal ********/void time ()/* update real-time clock  */{   sec100++;   if (sec100 >= 100)       /* 100 * 10 ms = 1 s */   {sec100 = 0;    flag1 |= 0x05;   /* set bit 0, bit 2 */    temp = 50;    sec++;    if (sec >= 60)    {sec = 0;     flag1 |= 0x02; /* set bit 1 */     min++;     if (min >= 60)     {min = 0;     hour++;     if (hour >= 24)     {hour = 0;    }  } }}}void scanLED() /* scan 4-digit LED and 4-key switch, if key pressed key = 0-3else key = -1 */{    int i;    digit = 0x08;    key = -1;    for( i = 0; i < 4; i++)  /* 4-DIGIT scanning */    {        P3 = ~digit & opto;  /* send complement[digit] */        P1 = ~buffer[i];  /* send complement[segment] */        pause(5);         /* delay a while */        P1 = 0xff;        /* off LED */        if ((P3 & 0x10) == 0) /* if key pressed P3.4 became low */           key = i;       /* save key position to key variable */        digit>>=1;        /* next digit */    }}void timeToBuffer(){    buffer[0] = convert[min%10];    buffer[1] = convert[min/10];    buffer[2] = convert[hour%10];    buffer[3] = convert[hour/10];}void blink(){    if((flag1 & 0x04) != 0) /* check bit 2 if set decrement temp until zero */     {temp--;        if (temp != 0)                {                buffer[1] |= 0x80;                buffer[2] |= 0x80;                }                else( flag1 &= ~0x04);      }}void keyexe(){    if (key != -1)    {        if ((flag1 & 0x80) == 0)  /* within 0.5 sec after 1st press                                    the following execution is not allowed */            {                flag1 |= 0x80;                delay = 50;      switch(key){        case (0): /* key position 0 */        manualOnOff();    /* service key 0 */        break;        case (1): /* key position 1 */        savetimeOnOff1();  /* service key 1 */        break;        case (2): /* key position 2 */        setmin(); /* service key 2 */        break;        case (3): /* key position 3 */        sethour();                  }                }    }}void sethour(){    hour++;    if ( hour== 24)    hour = 0;}void setmin(){    min++;    sec = 0;    if( min == 60 )    min = 0;}void savetimeOnOff1(){    count1++;    if (count1 == 1)    {    onHour1 = hour;    onMin1 = min;    buffer[0] = 0x00;    buffer[1] = 0x68;    buffer[2] = 0x78;    buffer[3] = 0x71;    showOnce();    }    else    {        count1 = 0;        savetimeOff1();    }}void savetimeOff1(){    offHour1 = hour;    offMin1 = min;    buffer[0] = 0x63;    buffer[1] = 0x63;    buffer[2] = 0x78;    buffer[3] = 0x71;    showOnce();}void manualOnOff(){    opto= ~opto | 0x7f;  /* complement bit 7 which in turn activates P3.7 */    if ((opto & 0x80) == 0)    {        buffer[0] = 0;        buffer[1] = 0;        buffer[2] = 0x68;        buffer[3] = 0x78;        showOnce();    }    else    {        buffer[0] = 0;        buffer[1] = 0x63;        buffer[2] = 0x63;        buffer[3] = 0x78;        showOnce();    }}void showOnce(){    int i;    for(i=0;i<2000;i++)    scanLED();}void keydelay(){    if ((flag1 & 0x80) !=0)        {            delay--;        if(delay == 0)            flag1 &= ~0x80;        }}void comparetime(){    if((flag1 & 0x01) != 0 )    {        flag1 &= ~0x01;    if(hour == onHour1 && min == onMin1)            opto = 0x7f; /* clear P3.7 turning opto on   */    if(hour == offHour1 && min == offMin1)            opto = 0xff; /* set bit P3.7 turning opto off */    }}void offmsd(){    if (buffer[3] == 0x3f)    /* if msd = '0' then put blank unstead */       buffer[3] = 0x00;}void pause(j)int j;{   int i;   for (i = 0; i < j; i++)   ;}