Program to connect to LCD display using 8051

Use 8051 to connect to LCD display. When the program is executed, the LCD display will show the digital clock. Modify the time by pressing the button B on the 4ⅹ4 keypad. You can modify the time (2009-08-04 18:57)

/*

Target：89S51

Program description: This example shows how to use Port 1 of 8051 to connect to LCD display. P3.3, P3.4 and P3.5 of Port 3 are connected to the control lines of LCD display. When the program is executed, the LCD display will show a digital clock. Port 2 is connected to the 4×4 keypad, which can modify the time. Button B of the 4×4 keypad can modify the time.

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

#include

#include

#define TIMER0_COUNT 0xD8F0 /*10000h-((12,000,000/(12*100))*/

                             /* Digital clock working mode*/

#define SET 11

#define TRUE 1

#define FALSE 0

#define putchar write_LCD_da ta

typedef struct {

           char hour;

           char minute;

           char second;

} time;

typedef struct {

           char year;

           char month;

           char day;

} date;

time now={23,59,0},display;

date today={04,05,29},tmpday;

static unsigned timer0_tick=100,mode=0,operation;

char co de dayofmonth[]={31,28,31,30,31,30,31,31,30,31,30,31};

char co de weekday[7][4]={"MON","TUE","WED","THU","FRI","SAT",

                         "SUN"};

char co de command[1][6]={"Watch",};

char co de int2char[]="0123456789";

char gotkey();

void display_time(void)

{

  gotoxy(1,0);

        display_LCD_number(display.hour);

        display_LCD_string(":");

        display_LCD_number(display.minute);

        display_LCD_string(":");

        display_LCD_number(display.second);

}

void display_date()

{

    char i,days=4;

  gotoxy(2,2);

        display_LCD_number(today.year);

        display_LCD_string("/");

        display_LCD_number(today.month);

        display_LCD_string("/");

        display_LCD_number(today.day);

        display_LCD_string(" ");

  if (today.month > 1)

        for(i=0;i<=today.month-2;i++)

            days+=(dayofmonth[i]%7);

        if( today.year !=0 ) days+=((today.year-1)/4)+today.year+1;

        if (today.year%4==0 && today.month >2) days++;

        days=(days+today.day) % 7;

        display_LCD_string(&weekday[days][0]);

  }

  int getdigit(unsigned char x,unsigned char y)

  {

        char keys;

        do {

              gotoxy(x,y);

              putchar('_');

              keys = gotkey();

              gotoxy(x,y);

              putchar(int2char[keys]);

        } while(keys>9);

        return(keys);

  }

  int gettime()

  {

        char temp;

        do {

             while((temp=getdigit(1,0))>2); //The tens digit cannot be greater than 2

             temp=temp*10+getdigit(1,1);

             if (temp > 23) display_time();

        } while (temp > 23);

        display.hour=temp;

          while((temp=getdigit(1,3))>5);

        display.minute=temp*10+getdigit(1,4);

        return(TRUE);

  }

  char monthday(char year,char month)

  {

        if(month==2 && year%4==0) // February in a leap year has 29 days

             return(29);

        else

             return (dayofmonth[month-1]); //The number of days in the month in a non-leap year

  }

  int getdate()

  {

        char temp,days;

           temp=getdigit(2,2);

        tmpday.year=temp*10+getdigit(2,3);

        do {

             while((temp=getdigit(2,5))>1); //The ten digit of the month cannot be greater than 1

             temp=temp*10+getdigit(2,6);

             if (temp > 12) display_date(); //The month number cannot be greater than 12

        } while (temp > 12);

        tmpday.month=temp;

        do {

             while((temp=getdigit(2,8))>3); //The ten digit of the day cannot be greater than 3

             temp=temp*10+getdigit(2,9);

             days=monthday(tmpday.year,tmpday.month);

               if(temp > days || temp==0) display_date();

        } while (temp > days || temp==0);

                                  //If the entered date is greater than the date of the month, re-enter

          tmpday.day=temp;

          return(TRUE);

  }

  static void timer0_isr(void) interrupt TF0_VECTOR using 1

  {

        TR0=0;

        TL0=(TIMER0_COUNT & 0x00FF);

        TH0=(TIMER0_COUNT >> 8);

        TR0=1;

        if(--timer0_tick) return;

        timer0_tick=100;

        now.second++; //second plus 1

        if (now.second==60) { //If seconds equals 60

                now.second=0; //seconds are restored to 0

                now.minute++; // add 1 to the minute

                if (now.minute==60) { //If the minute is equal to 60

                      now.minute=0; //Minutes are restored to 0

                      now.hour++; // add 1 to the hour

                      if (now.hour==24) { //If the hour is equal to 24

                            now.hour=0; //The hour is restored to 0

                            today.day++; // add 1 to the day

                            if (today.day>monthday(today.year,

                                today.month)) {

                                  today.day=1;   

//If the day exceeds the maximum number of days in the month, it becomes 1

                                  today.month++;         

//month plus 1

                                  if (today.month == 13) {  

//If month is equal to 13

                                       today.month=1;    

//Month returns to 1

                                       today.year++;     

//Year plus 1

                                  }

                             }

                             display_date();

                      }

                 }

         }

         if (operation==SET ) return;

         display=now;

         display_time();

}

static void timer0_initialize(void)

{

  EA=0;  

  TR0=0;

  TMOD &= 0XF0;

  TMOD |= 0x01;

  TL0=(TIMER0_COUNT & 0x00FF);

  TH0=(TIMER0_COUNT >> 8);

  PT0=0;

  ET0=1;

  TR0=1;

  EA=1;

}

void main (void) {

        char keys;

        init_LCD();

        clear_LCD();

        gotoxy(2,0);

        display_LCD_string("20");

        display=now;

        display_time();

        display_date();

        gotoxy(1,9);

        display_LCD_string(&command[mode][0]);

        timer0_initialize();

        do {

        keys = gotkey();

             if(keys==SET) {

                  operation=SET;

                  if ( gettime()) now=display;

                  if ( getdate()) {

                  today=tmpday;

                  display_date();

             }

        }

             operation=0;

        } while(1);

}